It's never a good time to buy electronic equipment. Something always comes out 2 weeks later that is cooler, better, cheaper.

A good 22x4 unit should sound very clean at volumes high enough to drown out any road and engine noise. At least the Kenwood I have does. I get distortion at (completely arbitrary number, I know) around 22-25 depending on the source, and generally listen at around 10-11. 17 is more than loud enough to drown out engine and road noise... And your passengers.

Whatever you get I'd reccomend making sure it has satellite tuner controls... That way if you decide down the road you want to get on that, you just need to plug the tuner into the back of the HU, and you're good to go.