advice on a new system

Hi everyone. I'm new here, and I need some help. Well, opinions and advice. I have a system in mind that I would like to put into my car and I need some people with a little bit more experience than I have.

My list so far includes,

Head Unit: Alpine CDA 9886
Front speakers: Infinity Kappa Perfect 6.1 component set
Rear speakers: Infinity Kappa 62.9i or 63.9i
Amplfier: Either the Rockford Fosgate T600-4 or the Alpine PDX-4.150 or the Infinity 7451a. They all have the requirements of what I want, at least 100 watts/channel and are stable at 2 ohms.

I'd like to build it 2 ohm, I can get more out of it for my money, I feel. At first I just want to put the speakers in then upgrade to a sub later on.

So, to start off, I have a 1997 SUbaru Legacy Outback. Its going to need a higher amp alternator, I know that for sure. There is no way my puny 85 amp alt can handle the system and the rest of the car. So, I'm down at least 300 there. Then upgrade the ground and power cables under the hood and what not. I was thinking of running 4AWG to the amp(s) and 12AWG to the speakers. Ill do 1/0AWG under the hood to ground and power. This is all tentative, thus your advice/comments needed.

My questions are these. What are you opinions on the things I have in my list? WIll they last? Will they work well together? Anything else I should take into account? Is there a better way to do this?

I'm on a budget, I'd like to spend less than 1000 on it all. I plan to do all of my own install and run the wires, save as much as I can on labor and whatnot.

SO, please let me know! Thanks in advance.

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1997 Subaru legacy Outback

You're on the wrong section here but first grounding cable to amp.  Don't run back to battery, you won't believe the interferance.  Local ground using an M6 nut and bolt, scrape the paint to bare metal and spray with a water excluder or lithium grease or use an existing bolt.  Make sure you run the RCA (phono)  leads well away from the battery cable again to avoid interferance. Don't forget to fuse the main power cable within 4" or 10mm of your source. Fuse rating =whatever fuse on amp + 5/10 amps. Cable size. Use the smallest you can reasonably get away with. Otherwise you will have a nightmare attempting to run and cable dress it.The first mistake novices make is to use a cable thicker than the main battery lead.  You can't get out what isn't there in the first place.  Again look at the fuse total on your chosen amp and buy a suitable cable for that load. There are kits available from  Scosche, DEI etc. buy the best.  Last point think about possible alternatives (sorry about the pun) to an alternator upgrade. A cap, a split charging system with a deep cycle battery or both. Unless you are going to sit for long periods with only the acc switched on I wouldn't bother with any of the above, just make sure your battery is good. If you are going to run the sub later run  spare battery and RCA (phono) leads now. That's it bar 2 points. If you're going to run a sub, don't bother with upgrading the rear speakers, you won't hear them anyway on the move and they will be a waste of time when the sub's installed*. Second point, think about placing the amp under a chair, saves cable, the run back to behind head unit or to the speaker cabling etc. 12AWG to the speakers? Wait till you try and get through the door grommetts! Good luck.* You'll have to cut the lower frequencies goin to the satelilte speakers any way at that time to get a clean sound.