There's a thread started this morning about this at MTBR VRC. While I've never used him, I've heard raves about his work. That being said, it sounds like he's a bit swamped at the moment and has been for quite some time.
On a side note.... After visiting the screen printer and watching exactly is done to make them, it amazes me how simple it is with today's technology. Basically I handed the guy an illustrator file, he fed the vinyl into the machine, and he hit print. The machine did the rest, and then he used an x-acto blade to cut the excess off.
If you can get a scan of the artwork you're looking for, and create the appropriate outlines in illustrator, then I think you're good to go. This is the hard part, and it probably takes a pro like Gil_M and Rody to do this.
On the cheap, they make paper that you can feed into your printer, which is basically a clear sheet with an adhesive backing. Its tough stuff, but if you have a color printer, it should work just fine. Note, this is the poor man's way.