What are you going to be hauling with it?
Figure out what the most weight you'll be putting on the trailer and go from there.
Lots of people don't get enough trailer. Or enough tire.
Recently upgraded to a 20' bumper pull with a dovetail and two 7k Dexter axles. Had them swap the 10 ply POS tires that were on it with Load Range G 14 ply tires.
I agree most people do not get enough trailer. When I purchased one to haul a Kioti 45hp tractor with loader attached I wanted to make sure it would handle that load plus any future attachments/equipment I might need to move. Since I already had a 14ft tandem 7500# trailer the new one I got was a 20ft with tandem 7000# axles for a 14000# rating.
Like you I thought the 20ft length and extra capacity of 14000# was worth the little extra cost.
