I run my parts through the shop I work for rather than dealing with them personally. Most businesses cater better to other businesses than to an individual. To them, there's alot more business at stake than just one small private job so they usually perform higher quality work at a faster rate.
I called a salvage yard from around my area about a certain part and was told they didn't have it. I then had my parts guy from work call and found that they did have it and they even delivered it to my shop.
If you all can find a shop with some clout to send your machine work through, you'll have fewer problems. I know it's not right, but that's how I do it.
Scott