A couple of suggestions from someone who has some real redneck welder, trailer building pals:
Don't screw around with regular paint. Go here
http://www.por15.com/ This stuff is a thousand times better than any paint. You don't want to mess around with "painting", etc etc more than once, this stuff ain't cheap but do it once and be done with it.
Coat the front of the trailer and any surface that is vulnerable to rock chips with bedliner.
Hmmmm coat the deck with bedliner over wood? Not sure but call and ask Line X or someone. Thompsons water seal SUCKS. If you do use a sealer etc., as opposed to bedliner on the wood, immerse the wood in something besides Thompsons and let it bathe in the hot sun......PENOFIN Marine available at Home Depot is pretty fair and hard to beat, any of the more expensive sealers like Penofin should work. Recoat every couple years.
Got some $$? Skip the POR 15 and bedliner the entire thing......close friend did his ENTIRE F250 in olive drab Armacoat, ran him 2K and that was for a fullsize truck.
As for the tires, get some of the heaviest casing all terrains (BFG Mud Terrains are 10 ply...someone else must make 10 ply tires I assume) and mount a bracket to carry 2 spares locked up (avoid theft). That gooey crap will get your tire guy upset (don't ask me how I know that).
Maybe a lockable steel storage box on the tongue? Keep a floor jack in there (easier than a stupid bottle jack...).
RR