Air hardening stainless seems to be less picky about how long you hold it at max temp than simple carbon steels (you don't need to worry about grain growth as much). I do a few AEB-L knives at a time, "quenched" one by one.
I know Evenheat makes programmable controllers that you can use your phone for. Probably be able to make a shelf yourself with a couple firebricks from the hardware/fireplace store. Sorry I can't help more, good luck.
My two cents:
You are likely to get ripped off.
China is currently persecuting Muslims, Christians, and any freedom loving people who will not adopt communist ideology and practices. Limiting financial support of the regime is always a good idea.
Obviously neither the history of the machine...