I put together a Drake station a couple of years ago - R4B, T4-XB, and
AC4. I got them all via eBay over a period of ~ 3 months. The AC4
cost me $65 (not in a speaker housing).

Those power supplies get listed on eBay a couple of times a month;
but...caveat emptor.

I'm going to check out that Heathkit link anyway, because I have some
more tube gear that needs similar capability.

Ted KX4OM