You've got some good suggestions here, but I'll add one more. I was checking out all the above mentioned places and finding good prices when I ran into something I couldn't find an answer for online. I was able to figure out who made the hubs and axle for my trailer, so I called them. They answered my questions, but their prices were full retail and the lady on the phone knew it and advised me of such. What she did though was refer me to a local trailer repair/rebuild center near where I live called Airport Trailer (Gainesville, GA).
I drove over to Airport Trailer and took my hubs with me. The guy at the counter not only recognized the hubs, knew the trailer axle they came off of, but also had complete replacement hubs with bearings and seals included in the price. Hubs were pre-greased, but the grease was not marine grease and he advised me of such. He made several suggestions on how to clean the axle, the bearings and keep myself clean during replacement, which you can see in the pics in my sig link where I am rebuilding my boat and trailer.
Costs/prices? Ironically, his prices beat the prices of anybody else I'd priced. Not by a lot, but by a couple dollars of the lowest outfit. Service and knowledge? Far superior to anyone else I talked to, including the local boat sales outfit.
My suggestion with all the information is to look up and make some calls to a local trailer rebuild place in your area. One that's big enough to refurbish Mack truck trailers down to the small ones. They'll likely have what you need very affordably and their knowledge will greatly help you solve all your problems.
