The Michelin XPS Rib (all steel construction) is an excellent choice for an E-rated (3042 lbs @ 80 psig) 16" tire IF you have 6000 lb GAWRs. If you need more, the Goodyear G614 RST is an all steel construction G-rated tire (3750 lbs @ 110 psig) IF your wheels can handle the 110 psig inflation pressure. If you have to buy new wheels, I'd go with the 17.5" Goodyear G114 or Michelin XTA 215/75R17.5 commercial trailer tires (both all steel construction) that are rated for 4805 lbs @ 120 psig. The 215/75R17.5 tire is about 1/2" less in diameter than a LT235/85R-16 tire, so fitment is generally not a problem.
All of the above assumes that you currently have 16" tires and 8 lug hubs. I've personally towed with all the tires listed above.
Rusty