There are a "few" good ones on here.
Rather than recommend one over another and possibly cause friction
, I'll let them chime in themselves.
Another to consider, who doesn't post here that I know of, is I.T. & D. Custom Gun in Ohio.
www.itdcustomgun.com He normally deals in new Douglas barrels, so not sure if he does recontouring (the rechamber part shouldn't be a problem).