System Selection / Wiring?

I have just gotten a new (to me) truck. The large kind that hauls freight across country. The dash speakers are only 3 1/2". The rear speakers are (currently)located Waaay back in the sleeper. I am looking to install a quality "Normal +" system in the cab. Something that I can crank up louder than your Mother likes but not nearly as loud as what most of you guys here build. Think along the lines of the high end factory system in a $50,000 sedan and we will be in the right ballpark. I recently drove a '05 Dodge truck that had "Infinity" badges on the A pillars and that system was pretty close to what I'm looking for. I am thinking that if I get some decent 3 1/2 units for the dash and block the bass to them and install some 6x9s in those wedge shaped boxes behind/under the seats with some reasonable amps I should be ok. Perhaps install a sub under the bed in the sleeper? This is my "Plan A". For a head unit I want iPod control, DVD, satellite, navigation. I am flexible about the navigation though since I don't know how well that segment works as compared to my dedicated Garmin GPS, (I plan to use the nav segment as a back up and in normal operation to give me an over view while the Garmin does that actual navigating - comments welcome. I am thinking about this: http://www.crutchfield.com/p_110VX7010/Jensen-VX7010.html?tp=5684 (Single DIN) Or this: http://www.crutchfield.com/p_110VX7020/Jensen-VX7020.html?tp=5684 (Double DIN) Any feedback on either/both units appreciated. Any reason to get the single or double over the other? Suggestions of comparable units welcome. (Only thing I see that I would rather change on these is the iPod input is in the front. I would prefer if it was in the back and I would run the cable into the glove box where the iPod would live. So my questions are: Is "Plan A" reasonable or do I need more? Assuming it is reasonable, the following questions apply... What 3 1/2 speakers? What is the thing called that blocks the bass to the 3 1/2s and what size do I need? (Do they even have a size??) Do I need 6x9s or can I get it done with something slightly smaller (to make it easier to mount them). Will a 6" sub do OK or do I need something larger? how much amp do I really need for that? I like my bass to have punch and not be all muddy and washed out. WHOMP. not BBBUZZZZ. It should feel like being punched in the gut, not being stung by 10,000 fire ants. If 1 6" won't do it, am I better off getting 2 6" or an 8"-10" (I'm not sure I have room for a 10, maybe an 8 though..) How do I wire 2 subs to 1 amp, do I need anything special just series? Parallel? them? With the above mentioned head unit(s) do I need an amp(s) or is the "stock" power enough to give me what I'm after? Assuming I do need amp(s), what do I need (Power, make/model) for an amp/amps? Do I need separate amps for the front and rear speakers or do the combined ones do ok? Lastly, (for now anyway) is Crutchfield a reasonable place to get this equipment or is there a better (less expensive) alternative? I know the speakers are the heart of the system. Without good speakers it makes no difference what you have connected to them it will still should like crap. My problem is I have been out of the loop so long I have no idea what currently is a good speaker and what is just an expensive waste of $. I have seen 6x9s from $29 to $500 for a pair. Just how high up the scale do I need to go? I don't mind spending a reasonable amount for this stuff but I don't want to "under buy" and I certainly do not want to over buy either. I hate to go to a stereo shop and ask there because they always try to oversell everything. I don't need enough (QUALITY) sound to wake the dead, just enough to keep the living from sleeping.... LOL.... Thanks in advance!