Threshold T-50 vs Forte 4 ?

My local dealer has a used Threshold T-50 for sale at $700. There are occaisionally Forte 4's on Agon for $500 or less. Are these two essentially the same amps? Would they be a good match for my Spica T-60 speakers and a C-J pv10a pre-amp? Is $700 a good price for the Threshold and can it be serviced if neccessary? Sorry for so many questions in one thread. I appreciate any feedback.