What's wrong with Hifonics?
O.P You could use any above, Just find one in your budget range, And make sure you get your gains correctly, so you wont be spending cash on new speakers due to clipping.
Sundown sells 4 channels also. The 100.4. And the 200.4, But the 200.4 would be a bit much. And they stopped making them.
okay thanks i guess i just have to look around
would the rockford fosgate r300-4 work