I ended up with a surplus office chair from work. It has wheels, spins and adjusts for height. I put it in my shop as I didn't have another need for it. Though I do sit in it from time to time to take a load off or think, I am also using it to work on projects or the parts of projects that are lower to the ground. Find it very useful. Oh, yeah, and I do roll around to fetch tools and stuff.
Well if you have crap luck getting what you need form Delta, you might try http://www.ereplacementparts.com/?gclid=CP2itLno2ccCFVBqfgodEuQLXg I know you have paid for the parts you are missing but if worse comes to worse the link is a pretty good place.