Bug Holes, Grizzley and several others keep a pretty good inventory of barrels.
This has been my go to for a while. There are a bunch of internet sellers that stock barrels by the best makers now, it's usually just a matter of doing a little searching to find what you're looking for unless you're looking for something really exotic, a quick search shows plenty of 7.5 twist 6mm barrels out there from several good makers. I prefer not to have the barrel maker do the chambering anyway, I'd rather deal with a good gunsmith that'll do what I want. I know several that'll turn around a simple chambering job in a few days. One of the best guys I know will chamber it while I go get lunch if I call ahead to make sure he's free.
There's no reason to wait months for a barrel to be made and fitted, it's silly. If you order an in stock barrel from one of the stocking dealers you'll have it in a few days and installed a few days later. I've used Pac-nor before and while they were OK they weren't my favorite, they weren't really any cheaper than others out there that I could see.
