I bought this one, yet to try it but looks good enough http://www.ebay.co.uk/itm/400665923747?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
Hm, I'm not convinced. I think that you need the small low friction bearings on the proper frame to allow the wheel to rotate as freely as possible. If you're only talking 5 grams out of balance I don't think greased axle bearings will have low enough "sticktion".
Brake disc side. Here's a good article. http://www.motorcyclenews.com/mcn/products/productsresults/parts-accessories/2006/november/sep28-05-how-to-balance-your-wheels/