I used parts from ebay and Smallparts (intended for home made 3D printers), paid a fraction of prices mentioned in this thread.
http://www.iceinspace.com.au/forum/s...ht=timing+belt
The pictures of motors are old ones, now I have 400s/r steppers and 1:5 timing belt reduction.
Electronics is Arduino Mega, motor drivers are Pololu A4988, 16 microsteps.