I agree with the guys that posted so far. I bought a rad carrier with loaded bearings and seals for 135 from ebay. Factory blems, but i certainly could not tell what was wrong with it. Bearings are thick and beefy. Best money spent on my R so far. Pop it in and ride - no broken knuckles.
Other than that, i have also been through alot of bearings with the two strokes on the rocky trails up here. OEM might be your best bet if your just going for bearings/seals, since they seem to last a long while. Seems like every 22 year old trike i get has its original bearings in it for me to replace.
'86 Tecate
'85 ATC 250R
'85 Tri-Z
'87 ATC 200x
'85 ATC 250R - Rider
'86 Tecate - Rider