Help with a budget-ish stereo setup

[rossmacd]

I need to pick speakers for my car. I'm using the MiMod for controlling the audio, but to be frank, I know nothing about speakers. Can somebody point me in he direction of a good speaker setup, and amp?

I'll be using a pair of small speakers up under the dash, because that's what is available for my car (1967 Mustang)
http://www.mustangsplus.com/xcart/19...-Speakers.html

These kick panels
http://www.mustangsplus.com/xcart/19...eter-Pods.html



And a sub in the trunk. That's it. I'm no audiophile, but I would like the stereo to sound decently good, without breaking the bank, or getting into compicated electronics, etc. There are some setups to put speakers in the panels above the rear glass, but I don't think I'm really that interested in doing that. I don't want to cut up the car any more than I already have, that's for sure. I could, possible, be convinced to put speakers in the door behind this
http://www.mustangsplus.com/xcart/19...-Moldings.html
but that's it.

I'd like to (and this budget is imaginary, I really know nothing about stereos so I have no idea if this is realistic or not) spend around $500 on speakers and amp, so not including the kick panels, or a box, etc. Is that reasonable? Can anyone make some recommendations for me? People start talking about RMS frequencies or things like that (that may not even be real) and I get lost... but I also don't really have a terribly strong interest to get neck depe in knowledge on yet another aspect of car building. Can you help a guy out?