Heads up on the bearings and bearing races. The majority of the "bubble pack" parts places and RV stores sell bearings that are made in China. They may be perfectly OK. But for my own purposes, I won't trust them. Remove one set of bearings and the race (also known as a bearing cup) and take it to a real auto parts store. Tell them that you want a complete set (2 or 4 wheel) of US made bearings. Equally acceptable to me are Canadian made, and any made in the EU. I have had excellent success with Timken and SKF bearings that are made in Mexico. FAG bearings, made in Hungary, I think, are also very good.
Most trailers use one of several common sizes. If the parts house says that no good brands are available, try another parts house, or a bearing specialty outfit.
For grease, I suggest Morey's red high temperature synthetic. It is pretty good about being water resistant. In 2004, I literally burned the travel trailer brakes on one wheel coming down the west side of Wolf Creek Pass. I backed off the brake adjustment on the back axle, and drove the remaining 500 miles home. The grease had discoloured, but it was still greasy. The stuff costs more than twice as much as the regular grease, but I think it's worth it.