I need to find a good amp for my MB Quartz's 6.5" Comp's and 6.5" mid woofers. 4 x 90 watts RMS @ 4 ohm's anyone please help me money isn't an issue I need my 1990 Audi Coupe Quattro to sound amazing!

My Hifonics zx6400 is 4 x 75w RMS and the thing is amazing.

Buy a JL 300X4 and turn it down a little bit its always better to have to much power than not enough. remember under powering a speaker it what blows it.

yup - underpowering is something a lot of peeps don't figure out until its too late. Clipping will OWN you! heh heh

But a JL300x4 is a bit much for needed 4x90 watts RMS @ 4 ohm's
My Kickers are the same 90rms and the Hifonics amp I have freaking rocks them loud.