Just ordered T5 pulleys and belts in sizes 14 tooth for the motors, 28 tooth for the X and Y, and 42 tooth for the Z. So I have 2:1 on XY and 3:1 on Z. Went with www.bearingstation.co.uk as they have a "price match guarantee" and were cheaper than the trade prices Brammer and RS give the company I work for.

Out of interest, how did you find the accuracy using the standard lead screws?