1AAuto is a forum sponsor, so buying from them helps support the forum. Kolak is also a forum-sponsoring vendor that can get you the parts you need (firstname.lastname@example.org is the email you need).
Other popular sites... www.rockauto.com
is extremely popular and usually priced very well ($65 for a Raybestos which uses a National bearing, same as everyone else). The various chain stores like O'Reilly, Napa, Autozone, Advance, etc, all carry the same bearings at varying prices. Often Advance has very good pricing for online orders if you search for coupon codes.
As far as axle seal replacment, yeah it's a major pain. You have to pull the axle shaft, diff cover, and the actual differential from the housing. Google "Dana 30 axle seal" and you will get dozens of how-tos. The good news is that the part is very cheap.