Just installed my radio, used the dremel to cut the speaker holes, which worked like a champ. No. 561 bit. It will rock!

Seperate battery for the radio and amp?

No, I have a tournament saver pro installed in the boat, so I don't worry about it running down I can jump start the motor if need off the trolling motor batteries. The jensen separates the face unit from the power source which I liked for mounting.