I know that you can buy Timken bearings (and a LOT of other RV stuff) here:
Trailer Parts Superstore - RV Parts & Accessories
and somehow, I know that my trailer (a '99 Safari 23') takes Timken bearing set # 17 for the larger end of the spindle, and bearing set #4 for the smaller end ( can't remember how I found that out) ...
but I can't remember whether the Timken bearings are Chinese made or not ...
either way, I DO trust Timken to have good quality control. Am I paying a few bucks more per hub for the name? Maybe, but I also think that I get Timken's long history in metallurgy (for a long time they made their own steel ... not sure whether they still do or not), their known quality manufacturing methods, and their QC. I just sleep better at night this way, and the few extra bucks are worth it to me. Maybe not for others.