jl amps are great, you don't have to worry about impedence since they put out same power from 4 ohms to 1 ohm (i'm pretty sure that's the range) and they are class D for the sub amps which is really efficient.

If you want some good stuff at a budget look at crossfire, cadence, can't think of anything else now
javi d
vroom n' boom

jZa
IHS # fo-six-fo-six

"real men don't ride stick"