I believe the speakers 80w per side
http://mobile.jvc.com/speakersandsubwoofers/cs-hx6949/index.html
The Speaker Power (Amplifier):
Get 1 4 ch. amp that puts out 150-200 watts per channel and wire it as you said....a 2 ohm load for each speaker. 2 speakers per channel. All speaker don't operate well at 2 ohms, but I've never seen any science behind it proving that it doesn't work just as well. Perhaps the efficiency is lost.
Get 2 - 4 channel amplifiers that are anywhere from 100-200w RMS x 4 @ 4 ohms. That means 100-200 watts per channel, times 4 channels, rated @ 4 ohms. You can run an amp rated for 500 watts to each speaker without a problem, the gain and volume settings (actually distortion) are what will blow the speaker.
one 8-ch. amp. JL Audio.
http://www.sonicelectronix.com/item_69570_JL-Audio-XD800-8v2.html
Which brand? There are 20 or so. You have the regular retail stuff, JL, Rockford, Alpine, Kicker, etc... You also have Soundqubed, CT Sounds, American Bass, etc... in my opinion, any of those brands will work fine.
The Subwoofer Power (Amplifier):
If your budget allows, install all of this stuff at the same time. Of course you can add on, but while you're running wires and such, it's easier to do it once. The principle is the same, find an amp that puts out more than required at the specified ohm level. Efficiency is more important here if you have a low amperage alternator. It doesn't matter what your amp is rated if you're not getting 14+ volts to the amps.
The Install:
Sound deadening. Do it. There are levels to it, so check out sound deadener showdown.
Rear fill is as important as you want it to be. So if you like to have speakers in the rear deck, do it. Don't do it because you see other people with it and don't stay away from it because people that don't have your ears tell you it's a waste. Front stage is generally more important though. I will stay away from 4 speakers in the rear deck and leave 2 (or all) blank just to allow some of the soundwaves from the bass to enter the cabin. You can mount 6x9's under the 1/4 window....or the upper 1/4 trim. Pics are available easily with a google search.