Precision Measuring Equipment
http://www.use-enco.com/
They were just about the best prices I found this side of dealing with ebay, shipped quickly.
A cam degree wheel kit also comes in handy. As well as a set of good torque wrenches (I bought some Armstrong torque wrenches from Enco as well - 3/8" 0-100 and 1/2" 25-250).

