Hi and welcome!

I am in the same situation as you. I'm no audiophile or car stereo expert. I also would never turn the volume up to window-popping levels, so I didn't worry about the speakers. But I am an electronics engineer, which helps to figure things out.

For the semi-deaf (like myself) the quality differences between amps are not noticable (or at least only barely). Besides, in a car you find so many other things deteriorating the sound quality, that the amplifiers are imperfections get lost in the (road...) noise. The cheap amps mostly rely on integrated drivers that are pretty much defining the quality, not the amp design. So I went by one simple criteria: CHEAP! I paid $60 for a 4-chanel amp. It says 80W per channel, but that's marketing hype. Besides I won't turn it up (see above).

I'm not quite done installing it in my Honda Insight, but I'll keep you posted...

Oh, I may end up replacing the factory speakers, just because they are sooooo baaaaad that even I can notice!

Armin