See this thread? Threads like this are why I both love and hate this site. I love all the great information and points of view, but I hate having to re-think everything and put off building what I thought I wanted. :D
Seriously, thanks for the input guys. I'm looking for something that I can build and operate economically. The two-brick forge is supposed to heat quickly and be fairly efficient with regards to gas usage, from what I've read. I had originally considered building one that I can hook to my propane tank from the grill and would still go that route if it makes sense to do so. Reading Chris' reply above makes me think that's a good way to go.
Here's the one I was thinking of building...
Two-Brick Forge If I can find a freon tank and the fittings I need to do propane, maybe that's a better/cheaper way to go?
Hmm...