Home theatre power amp questions

I currently have 3 PSE Studio V and 1 Sudio IV amps driving the system. One of the Studio V need repairing and it seems nobody fixes them any more. I have placed an add looking for 1 or 2 amps and we will see what happens. The two questions I have are :
On my paperwork from 1997 it says Vandersteen cross-over installed in PSE Amps. If I find some amps will they still work
What would be a alternative to the PSE amps and I would I have to buy a new pre amp???