So I bought an ipaul amp but it ended up getting screwed up in the install which apparently voided out the the warranty so now I need to buy a new one.. I have around $400 to spend but don't want used. Any suggestions for an amp that's equal or better than the ipaul I had? I'm also only looking for 4-channel amps. I have rainbow components in the front and memphis coaxials in the rear. I planned on upgrading the speakers but need to replace the amp first. Thanks a lot.