Thanks again for advice everyone!
I decided not to go with soldering furnace. I'm not really in a huge hurry so I guess I'll keep my options open. Forges pop up occasionally on Craigslist here in Denver but the Johnson was the first gas fuel forge that I'd seen and since burning solid fuel in my backyard is not ideal, I thought I might jump at it.
I recently completed my first knife, so I am definitely still a newbie. I've got a decent little workshop set up but a forge and a proper belt grinder are still high on the wish list.
I'll look into some classes and perhaps take another stab at building a forge. My last attempt was a rather pathetic MAP gas job that (sort of) worked but ain't nothing to write home about.
I really appreciate the info and advice. I hope I'll be able to contribute more than just newb questions to the forum soon.