This is a fairly broad questions, there are many different types and brands of what you're looking for, I would suggest visiting your local electronics store, checking price, and-shopping around.
The Alpine monoblock is fairly new to the market but has many great features including bridgeability, impedance mismatch protection and a built in cooling fan. The power supply uses a switchmode converter to change the incoming voltage and it also eliminates noise coming from the engine and other electrical devices in the vehicle which could ruin your fat sound system.
