I have had bridge and/or end pins made by:
Bob Colosi...
Custom Inlay...
Gurian...
Colosi and Custom Inlay will make custom pins to your specs. They will even copy pins that you already have (in another material or with a different dot)... which is the best way to insure that your new pins fit. Gurian takes the "one size fits all" approach... so I had to sand Gurian pins to fit.
You can also get pins from:
StewMac...
LMII...
My choice of pins is mostly aesthetics... do I want a light pin with contrasting dot, or a dark pin with contrasting dot? Do I match the bridge or contrast with the bridge? On my DV-73, I have horn pins with turquoise dots... on my turquoise DV-72, I have bone pins with turquoise dots. On my malachite DV-72, I have bone with Ab dots (which have a nice greenish iridescence). On my D-35, I chose bone with 4 mm tortoise dots, to match the pickguard...
For dark pins, I prefer black horn over ebony... horn takes a real nice glossy polish, while all the ebony pins I have seen are more matte finish. I have also heard that, being just a bit denser than ebony, horn is a little bright sounding than ebony, but warmer sounding than bone (if you believe pins make a difference).
I am in the market for new pins for my new (to me) D-70, which came with ebony pins. With its maple binding and aged lacquer, the D-70 has a very gold look... so I was thinking black pins with 4 mm gold MOP dots... I was thinking black horn, but Custom Inlay (link above) also makes black-dyed bone pins, and wondered what they might be like. Might get a set of each, and A/B them for looks and tone.... or maybe go with something more exotic, like fossilized walrus ivory? Decisions, decisions!