I second what Frosty said about over thinking the charcoal forge. I also agree with wanting two set ups. I have tweaking to do on my gasser to get it up to welding temp (actually temp isn't the problem, It's plenty hot enough, but it makes scale in the fire and my most effective attempt at choking the burners consisted of a strip of duct tape partially obscuring the intake venturi's, anyway more work necessary and I haven't had time) I can make a forge weld work with a fire on the ground and a hair dryer, but no matter what flux I use, I can't weld in an oxidizing fire. grrr.
I Love Charcoal!, in part because it's easy to localize your heat and in part because it's so "traditional". I once made a working "field expedient" forge in mexico with a pile of rock, some dirt mixed with ash and water to make it harden, a rusty pipe, some sheet tin for a wind catcher and a fan made of downed palm fronds. It didn't get to welding heat, but that's because I didn't have a proper bellows, blower or electricity to run a blow dryer. I also didn't have the patience to use the natural bellows contained in my rib cage...besides it makes you lightheaded. The charcoal was just laying around and I wanted to do a little forging. The anvil was a rock...
I made several hooks, a poker, and a rake for the fire, and over all, just had a good time making such a primitive set up work. It's easy to get caught up in having the best tools for the job, but the truth is, that almost anything will work, otherwise our ancestors would never have gotten beyond flint shards and twisted bark. Good luck and happy forging.