I'd check out the Lanzar Vibe amps also.
You can get plenty of power for a lot cheaper.
Vibe 269 - 2x500 watts RMS @ 4 ohms. $169 at ikesound.com.
Even if it doesn't put out *all* 500 x 2, you're still getting a lot of amp for the money.
I run two of these amps (the 428 - 125 watts x 4, and the 248 - 300 watts x 2) and I'm very happy with them.
They are at least on par with Rockford for quality - I know, I had Rockford before the Lanzars.
2002 Sunlight Silver Metallic Mazda Protege5