There's absolutely nothing wrong with having a driveshaft shop cut down an already existing shaft to the dimensions you need. I would suggest a front shaft from any pre-2003 (or whatever year they went to independent rear suspension) Ford Explorer. They have a fairly large diameter, thick wall tube and a CV joint at the transfer case end. You'll need the proper Torx bit to remove it at the junkyard.

I use these on my CJ's and cut them down myself.

Tom's prices aren't any higher than anyone else's for a new shaft. They are all new parts and the DOM tubing used is not cheap.