Where to get a barrel blank machined?

I’ve been tossing the idea around of buying a LW barrel blank and having it machined to drop into my Maximus and have it threaded for a suppressor. There are a ton of companies/people that machine barrels, so I was wondering who has a decent turn around time with quality work and a reasonable price? I’d like to get a ballpark of how much I’m going to be spending on this project before I ask the warden for funding ?
 
Two names come to mind Sergio at BNM products, and Bob Cothran, both did a lot of Disco conversions and after market stuff. The newer barrels are offered in a threaded variety from Crosman, and are I believe longer than the old Disco. This eliminates the fill probe problem. LW in Georgia has a.430 and .470 diameter barrel. The factory Disco was 7/16" which is .432 The smaller diameter barrels were a special order, along with a minimum amount needed. I'm pretty sure all these barrels only go o 24" in the smaller airgun calibers, better than that length was like 10 minimum with a long wait. I's been several years since I played with them, hope this helps.