sound quality amplifiers

After a friend used Sound Integrity subs in his home theater system (2 - 24") and the sound floored me by the clean, ultra wide band and accuracy of them, visiting the site I was looking at the amplifiers, components and SQI subwoofers. I watched reviews and dynos on them. They seem clean...

I am looking for opinions on a good sq amp that is less than or around 500 if that's possible I know it cost more for sq. needs to be 600 watt rms at 4 ohms for a svc jl w3 13.5 the sub will get upgraded later thanks

I'm in the process of rebuilding, currently have alpine type r's up front, type s's in rear, and a type r 10 in the trunk...looking for a QUALITY amp that will produce enough power. I'd love a PDX 5 channel, but I just can't drop that kinda money on an amp, as much as I wish I could. I'm not...