On a tight budget, I'd consider an old Marshall Valvestate. Really good-sounding amps for how much they go for these days:
Not perfect-sounding, but for how much you can find them used these days, they pack a lot of tone.
IMO, a hell of a safer bet than *most* Crate and Behringer stuff.
Even though I'm not the biggest fan of Spider amps, a Behringer modeling/digital head would be a downgrade from a Line 6 amp. Big time.