Hi, there have been several threads on this. I suggest you look them up for more details. However, in brief the two best amps I've used with Vandersteens (personally) have been the Quicksilver V4 Mono blocks and the BEL 1001 Mk V amps. The V4s are more tubey and will have that bloom you can only get from tubes. The BEL Mk V is in another class entirely with more detail, neutrality and musicality. Since they're about the same price new I'd get the BEL hands down. However, if you can't live without tubes, the V4s will not dissappoint.
Good luck!
Good luck!