Here's an
old post that lists different bearings available; being so old, some info is likely outdated:
Rod bearing suggestions
Here's a link which describes the difference between Federal Mogul standard and racing bearings; I'm not recommending you buy from this company, but the info is good. You can run performance bearings on a standard-grind crank, but you loose some bearing width, which
might offset the positive aspects of the better bearing.
http://www.ronsraceshop.com/products.asp?ID=1103
Dan