Need opinions on this set-up

Well I'm slowly narrowing my search for the perfect car audio system for me and I could use some opinions from those of you with more experience than me....which is probably everyone on here.

I'm looking for a high sound quality system to go in my RX8, I'm keeping the stock head unit since its a lot of work to change it out so I'll probably use a Audio Control 6XS and I have a custom fit fiberglass sub box for one 10" sub which has .8 cu ft. of airspace.  I'm looking for a set of front components, something to replace the rear 6x9's, one 10" sub and of course amps.  I'm looking at either a 5 channel amp or 1 mono amp and a 4 channel amp.

Here's what I'm considering:

JL Audio 500/5 or Crossfire vr705d amp

Adire Audio Koda 10D4 sub

Adire Audio Koda 6.1 components

Has anyone used or heard the Koda 6.1's? I will have to order them online so I won't be able to hear what they sound like before ordering them.  I also need suggestions for replacements for the rear 6x9's, I was thinking of getting some 6.5 coaxials instead of them but not sure what brand to go with. I'm going to upgrade the stock wiring but I'm not sure if I would need a cap with this system or maybe upgrade the stock alternator and/or battery.  If anyone could give me some opinions or suggest other options I would really appreciate the help.

Krf, thanks for the great reply and I really appreciate it, I have a few questions you can hopefully reply to.  I'm thinking of going with a 5 channel amp simply for space reasons, I would really like to consider the Memphis belle amp but I'm having trouble finding out if they're even available in Canada.  I noticed on their website that they don't have online retailers so my search continues, if anyone in Canada has info on this it would really help.

Regarding your opinion on rear fill; are you suggesting simply disconnecting the rear 6x9's and running without them threfore only requiring a 2-channel amp for the fronts and a mono amp for the subs? Or just using the stock 6x9's connected to the amp or running them off the deck?

I started looking at the Brahma sub, looks really nice.  It says 1600W rms, I know this isn't necessary and is probably overkill but I'm wondering if 300W rms is enough to make use of this excellent subs potential.

With the front components I need an explanation of on-axis loading, I'm not sure what this means.  My plan was to simply install the components in the stock locations, woofer in the lower door and tweeter in the sail panel.  Perhaps Forbidden can comment on component location for an RX8. 

I could also use some help explaining the Audio Control 6XS that was recommended to me, I've never installed a system that retained the factory head unit.  Since I will have crossovers on the amp and the components have their own crossover, is this necessary? I was looking at the LC6 which seems like it would do the job and has an optional sub control.  The 6XS has rca inputs so I would have to wire in rca's tot he stock wiring whereas the LC6 doesn't have rca inputs.If someone could explain the other differences between these and if I really need the 6xs for my planned system that would really help.

Ok, I've rambled enough, thanks again for your guys input and putting up with my rookie questions.

Where in Canada are you? Personally between the Memphis and the Crossfire, I will go with the hand built Crossfire VR705D, I have used this amp many times in similar installs. Throw the Eclipse PA5532 amp into this mix as well, it is a wolf in sheeps clothing and is a gareeaaaat amplifier. Just did one of these amps last week in a VW actually. As far as the rear fill goes, I like rear fill. That said though, keep the rear speakers down to a dull roar if possible. Meaning keep them to a basic but good coax or pointsource (or if you must a good component like the one I am doing presently). Try and match the front and rear speakers by brand for tone / timbre matching. For the front speakers, on axis means having that speaker in the same point of directional travel of the output of the speaker. Meaning the tweeter needs to be mounted in very close proximity to the woofer, either directly infront of or directly above.

Now while this may be the "ideal" way to do things, in some vehicles without a good amount of work, it is hard to do. The other thing to consider is things like your passenger legs being in the way of the tweeter in that door. Now if the vehicle had the BOSE (ewww) system in it, disenfect your hands and from now on wear rubber gloves. The door speakers in the BOSE system are almost 8" across, thus you will have to make a mounting adaptor. (the ones I just did are mirror plexiglass). The customer wanted the tweeters in the stock location and they sound great for most people. If you are a serious die hard that cost is no object, then the factory spot might not be the place to mount them.

The 6XS is much more than a great crossover, it is also a stellar platform for signal integration. If this is the BOSE (ewww) system in this vehicle, care must be taken when placing the Bose speakers in the garbage. Replace the lid tightly and securely and if a lock is not available, weight the lid down, we can't afford the BOSE making a break for freedom. If it is the BOSE system, the main amp is in the center bottom of the rear deck and will have 5 grey wires going into it. These are the preamp lines. Find the front and rear, + and - in each line and solder on rca ends. Done and done. Next it is a line driver and signal balancer. Important as the RX8 has a huge signal on the front lines and next to none on the rear. It then derives a sub channel and gives a plug in remote level control to operate it. The bass remote can be taken apart and installed in one of the factory knock out panels to the left side of the steering column. Trust me, do the 6XS in this case, it offers far more value for your investment.

PM me for info on the amp and speakers if you are interested.

Well now I have another amp thrown into the mix to consider, JL/Memphis/Crossfire/Eclipse... any of them will work well for me I think so I'll probably choose the one that I can find for the best price.

I started looking at the Boston Acoustics Z6 components, any opinion on these?  The koda components and Brahma sub don't seem to be available yet. at least not in Canada through Creative Sound Solutions.  I'll pm you Forbidden with some component fitment questions specific to the RX8.

You've convinced me on the 6XS, all I have to do is find one for a decent price. Local shop quoted me $400. 

Thanks again.