I'd just type in Custom Western Holsters and see what pop's up. There are so many guys making Holsters that you are bound to find a style that fits what you want.
Finding a personalised Holster is like Comedy, all about timing...
It seems that builders just up and change designs on a whim. They'll have a design pop in their heads and just build it!
Personally I carry my 4 5/8" New Model Vaquero in a cusom Sholder holster that I got through a dealer on the net. They were closing out some exhisting stocks of Custom 1880's holsters and I saw mine. I got it for only $59 believe it or not!!! It's a simple design with only a border cut of two lines and a center pattern.
The main thing was I didn't want any front, across the chest, straps. This way the holser dosen't give itself or the fact that you are armed, away! I looked around once I decided on a sholder rig and the 1880's style holsters were famous for not showing their straps.
I wanted a full coverage, butt forward rig with no bullet loops.
Don't be afraid to look through the Closeout sections of websites. Many big manufacturers have a sale section to their sites.
HTH,
ZVP