CJ’s solid state products are very underrated. I would get the 350. I have the matching preamp (Premiere 18). It still sounds great.
The Premier 350 is a little old at this point. If you want something more modern, that sounds better and has similar DNA, consider the PS Audio BHK 300 monos or even the BHK 250 stereo. I’ve owned the Premier 350 and felt the gain was too high for that amp. Bascom King had his hand in the development of all these products and you can hear the similarities but perfected in the PS Audio BHK amps. They are truly under-rated and are hybrids with tube inputs. They are wonderful amps.