Just so it's up front, I have been using the search feature but I do want to get a FEW posts on this site and I enjoy discussing rather than reading, so here it is:

I have an 88 Formula 305TBI with the stock speakers and a Sony Xplod CDX-GT100 headunit I installed. The speakers are garbage and one of them is blown, so for Christmas I'm looking to get some replacements that might match up well with the headunit. It's nothing special, but I want at least a decent sounding budget setup that I can just plug in to the stock wires for a simple swap.

I believe pretty much any 4x6 speakers will fit up front and the same with the 6x9s in the back, but I'm not too clear on how much handling power I should have for this head unit, etc. The specs say "CD player with built-in amplifier (17 watts RMS/52 peak x 4 channels)". So if it says 17 watts RMS, does that mean that the speakers only need to be listed as 17 watts RMS handling or higher? What does the 52 peak x 4 channels mean? I know this unit has an output for a sub, but I don't have one hooked up and it's not a five-channel headunit, so how does that affect the output to the four main speakers?

I'm new to this car audio stuff so bear with me if these are simple questions. I will continue reading up and hopefully answer some of my own. Thanks!