http://www.bocabearings.com
http://www.hatterasoutfitters.com
Remember, you have to figure out first what you want, in order of increasing rollability and expense:
1) Stock factory bearings
2) Abec 7 Stainless
3) Ceramic
Remember, for optimum casting performance your bearings should be cleaned with an organic solvent...and then properly lubed before you install them.
-WW