I finally got to try out my new welding machine last nite!! I bought a Hobart Handler 140. It's made by Miller, has all Miller parts, and is pretty reasonable - $475 for the machine, gas gauge, hose, and a spool of wire. It works great!!
One feature I really like is the Purge feature. If you are running gas - which I will be once I start welding in body panels w/short arc - you can switch your amperage knob to Purge, pull the trigger, and set your gas flow rate without rolling (wasting) wire through the whip.
I am building a welding cart from an old go-cart; I couldn't find a wheelchair, KCMongo. As soon as I'm done I'll post it on my website.