I would avoid Crate. I have a very large place in my heart for their sound, but fact is their reliability completely sucks. Every person I've known with a crate amp/head had had problems with it without exception.

With tube amps I think it's better saving up and getting the best you reasonably can. If you get your hands on something like a mesa mark 4 or a laney VH100r if it fits your style you'll never need another amp.