I don't know if this would be one that meets your needs but it's simple to make and it sure meets my needs and brings my blades up to critical temp pretty darn quick.
All ya gotta do is get yourself a refractory fire brick (the soft kind) (you can google it and order on line) and drill it all the way through length wise and waller it out to around an 1"-1/2 wide by 3" vertically then drill a hole in the side about midway just big enough for your torch tip to fit through and there ya have a forge.
I used one like that for awhile and then decided to buid a stand for it and thats what I'm still using today all you need is enough scrap steel to encase your brick with kinda like a little stove and I just used a few rail road spikes for the legs, heres a pic.....
Hope you find this helpful and look'n forward to seeing what ya come with.