Another excellent place is
http://myworld.ebay.com/racergirlsrock They have a complete set of A-arm bearings to do all four arms of the LT's with seals for $50. They also have many many others.
Most importantly, when buying bearings from places like VXB, you need to know the bearing size or number. Many places that sell just bearings and seals don't always know what machines they'll fit so they just list them as size and part number.
When replacing the axle and wheel bearings, many times you won't need new seals which just increase the cost anyway as you usually can only get them in a full overpriced kit. Any ball bearing can be purchased with a ZZ or an RS or 2-RS after the part number. This means it has a metal seal around the balls (ZZ) or a rubber seal (RS) or two rubber seals (2-RS). If you buy the bearings with a seal already installed onto the bearing you can just reuse the original seal that you normally put in after in after installing the bearing as a dust and dirt seal. And the cost between a bearing with a seal on it and one without is usually a couple cents difference.
When using sealed bearings, be sure to remove the inner seal on both bearings and fill the carrier/hub with grease. It is easily removed with a pick or knife tip.
When doing A-arms, a kit is usually best unless you can get the seals new cheaply. They really need to be well sealed to offer any lifespan. Usually by the time you need new arm bearings, you need new seals as well anyway. This goes for the swingarm bearings and seals as well.
While some bearings are only available from the manufacturer, like the cusion lever big bearing on the LT500, places like VXB and Racergirlsrock can save you some serious cash.