I'm leaning towards the BAT VK-31SE (good deals on out-going model) & BAT VK-250, which I will demo. this week, though it won't be cheap at $12K-retail (2X the cost of my VK-300xSE). I'd rather not mix-and-match pre-amps & amps. Manufacturers of this caliber go through a painstaking process when voicing (tuning) these components for optimal mating, and I doubt that I could better. The ARC LS25MKII & ARC VT100MKIII are my second choice, at around $5.5K-used, though Im hesitant to take on the bulk, heat & maintenance of a very large tube amplifier.