I get all My bearings from here
http://www.avidrc.com/shop/?action=payment
Here is a list of all the ones you need.
5x9x3mm (3 pcs)
4x8x3mm (2 pcs)
10x15x4mm (4 pcs)
5x8x2.5mm (8 pcs)
3x7x3mm (2 pcs)
5x10x4mm (8 pcs)
or you could get these but I 'm not sure if they are reliable...
http://cgi.befr.ebay.be/3racing-Ball...sid=p1638.m122