Thanks everyone.
I'll be making a run to the stores this afternoon to buy rollers, gloves and brushes. Considering there are many ways to skin a cat (as shown by all of you) I will probably see what kind of rollers I can find and go from there.
I'll be shooting for the west marine rollers (but I don't know if the boat supply stores around here are open today) if I can't find them I'll probably get the shortest nap rollers I can find at home depot and work fast. I'm building the super size weekender so everything is flat and i should be able to work fairly quickly and I'm not worried about it being perfectly smooth.
I inted to work in the following order:
-I intend to do a coat of epoxy over the entire trailer
-put extra on all the end grains
-make a wood flour filler and fill any gaps that I have from my most excellent measuring ability
-fibreglass some of the seems and my inner fenders
-one more coat of epoxy over the entire trailer, maybe I third if I have any epoxy left
-apply two coats of paint, don't know what kind yet. Maybe a tremclad RV white.
Thanks everyone for all the info.