[72 cheyenne pdx]

Here is what I would do:

Front Speakers:
5.25 components to run on deck power or to an amp.

Rear Speakers:
5.25 or 6.5 components to run on deck power or to an amp.

Subs:
use whatever you decide, I recommend 10's, and power them with a mono or a 2 channel amp.

Now for Amps, there are a lot of brands out there. I may say one version to go with and the next 10 people you talk to or post on here will give you 10 other brands. So I will leave that up to you. The rating though is what I will recommend. If you decide using an amp for the highs/mids, and depending if you are putting all components on a amp or not will determine if you get a 2 or 4 channel amp, I would find an amp with at least 30W RMS per channel and would probably get a 50W RMS per channel. Now I am unsure what Subs you have or are getting, but I would get at least an amp that produces 200-250W RMS. Good Luck with the system.