Can someone reccomend me a smaller tube rackmountable power amp to go with my Mesa 400+? I am going to use this to power a Bergantino 210 with my 400+ powering my Bergie 610. Must be racmountable, and I prefer a mono block but would consider a stereo amp as well. I am most likely going to look used, so feel free to put in discontinued models as well. I would also need at least 100 watts, or something close to that. Also, what would be a good way to set this up? I was thinking of maybe taking the DI, but I think that I want to biamp and would also like to leave the DI open for the occasional PA. So, I think maybe a crossover going in after the FX loop with the lower freqs going back into the 400+ and the higher freqs (maybe at about 2000 hz? Reccomend a freq if you can) going into the extra power amp.