Parts arent hard to find for theese amp But they can get expensive to fix.
Also can be very time consuming to repair just depends on what your willing to spend for parts and how much time you want to put into this amp.
My friend just repaired one of thoose amps and spent about 250.00 in parts alone ( all new outputs,new driver board, resistors, diode,transistors ect.
He had about 20 hours of troubleshooting and replacing parts.