The AR I/50 and Margules I-240 are both excellent. The Margules is class-A. There is a head-to-head comparison online (YT) with intro and commentary in Spanish, but with extended play by both units.
The newer version Willsenton R8 shouldn’t set you back more than $1500 and with a little tube rolling will get you a very nice sounding 45W AB using KT88s, but will also run EL34s. With Amazon, you would have some trial time to decide.