I have some money in paypal, and was thinking about buying new bearings for the trailer...

Are they all the same size? Or do i need to pull what i have and get the numbers off of them?

If you have a 5x4.5 hub they are probably L44649/L68149 Bearings and a #84 spindle. However there is a small chance they are not.

I carry a whole preloaded hub with bearings and seal wrapped with saran wrap when I tow any of my trailers any distance. When I go far into Mexico I bring a whole spare axle...