Jake:
Almost any luthier who works on instruments beyond double basses does inlay as part of their regular work. If you need to have them inlayed, Randy Allen, of Allen Guitars and luthier supplies sells mother of pearl and abalone dots in a variety of sizes for about $20 per hundred; most other places charge you close to $20 for a half dozen or so. You should be able to do it yourself with a small drill bit and a little glue. Use a good tuner to find the exact spots you are after.
I'd recommend using a simple white out pen; if you change your bass setup and / or strings, the location of the marker can change slightly, leaving you with a nice inlayed piece that is innaccurate.
j.
www.condino.com