Phoenix gold rsD500.4
Diamond D9800.4
Eclipse XA4000
Zapco C2K-4.0X


thats just a few. If you look up prices, you will see they range anywhere from a 3 or 4 hundred, to well over 1500.

You just ahve to know whats in your budget and how much you really need. Unless you are running some very high end components, with a high end electronic x-over, with a very high end purpose built install. You arent going to notice any real difference between any of those amps.