What's the best distributor for stock gears?

I need some gears and I have a bunch from CD players and things, but the ones I need require more specific ratios than I can get with found stuff. Does anyone know a good distributor of stock gears with a wide selection? (I ask because I don't want the cost of custom-making them if I can get a good selection AND a good deal) I am based in the US, but any international ones would work if there are none here or if any folk across the pond need some.

Comments

[ewilhelm]

I've ordered all my gears from McMaster, Small Parts, or a distributor called, I think, SPI-DI or some similar letter combination that I can't figure out with 5 minutes of web searching. Obviously, their branding wasn't very good.

[ewilhelm]

I finally remembered: http://sdp-si.com/