I understand that IPOR uses Driveline Specialties. Had them do mine because Mtn Run wasn't answering the phone due to owner illness. I agree with Bob's assessment of Driveline Specialists. Next time I will look towards Baltimore for options.
Unaware of Mountain Run at the time, I had Driveline Specialties do my front driveshaft. They were unable or unwilling to use thick wall tubing. It was thicker than stock, but not by much. Creased the first time out.
Got a one piece from Tom Wood for a Tacoma. Brand new it was out of balance at 80. They were more than willing to work on it but cost the same to ship it as to take it to Driveline Specialties out of Lorton. Those guys said the shaft was out of balance and not clocked off by two teeth. Now its back in the truck and I get a different vibration at 70 but I know my pinion angle is off by ~3degrees. One thing to work a project but to run into issues repeatedly gets old. Let us know where you end up going and how it turns out.