Not me. My guys all stop making them at around 8 or even 10 gauge. You can often call the information line at your supplier and ask for the e-mail or phone number for whoever does the artistic machining on custom jewelry to get an estimate directly from them. Most will do anything you ask for, but it will cost you. The last three times I have priced custom pieces too large to make by hand (and 6 gauge is), I got quoted prices for one-offs at about what I could have gotten solid gold stock items for. Full customization is expensive.
(An example of what I was seeking the last time I got quotes, was a 2 inch long staple-style surface bar made at 4 gauge with stainless steel that I could try turning suspension piercings into permanent piercings like a couple of the fellows on BME are doing. 485.00 per was the lowest price I got from a reputable manufacturer's customization dept.
If you get the same sort of quotes that I did, you might look at getting 8 gauge stirrups and wearing them strung through a 6 gauge flesh tunnel. But check on the ID vs OD on those items as the tunnels thickness vary a lot and you might need to go to a 10 gauge stirrup if the tunnels are nice and thick.
a.k.a. Mitch E. "Sticky" Gander