ABEX, the tube amp I've used in the past was a Dynaco ST-70 for the tweeters. I've used a Technics SE-9060, and Bryston 2B-LP for mids. Also, ESS M-500, Adcom GFA-545, and Bryston 4B for the woofers. But really, you need to select an amp that works best for you and your speakers, rather than listen to faceless people on the Internet.
For crossovers, I have a couple SAE 4000s for the fronts and I use a dbx 223 for the rear. I use a couple DOD 825s for another system.
I actually don't use a tube on the tweeters any longer. I now use a Bryston 4B and am happy.