Tire Search for 5th Wheel

After selling our home in FL, We purchased a 2010 Alpine 3450RL by Keystone last Oct. 2013 in IN where we had been workamping, drove it out to TX then back and around panhandle of FL down to Vero Beach by mid. Dec. In Jan. on way to Super RV show in Tampa, tire blew out after 30+ miles on SR60, but we were riding on the rim before a motorist pointed it out to us. Spare with rim put on and we were on our way. Bought a new tire over in Tampa area. Plus hubby bought Tire Minder sensors and kept checking them along the way up to St. Augustine then back to Vero. (Note: All traveling being done in Cold weather.) Sun. May 4th, on I-95N passing Brunswick GA front driver side tire on our 5th blows, and right away I saw it going up in my driver's side mirror. Took out wiring for elec. brake on driver's side. Good Sam road assist promptly arrives and changes to spare. Up the road another hour and at Savannah exit, second driver side rear tire blows. Again, I saw it all in my side mirror, along with panel damage. This time Good Sam's sends a Goodyear person with a new Marathon tire we had to buy and changes it all out. After this second delay of a few hrs. we made it up to Hardeeville, SC where we are staying in a new campground until we can get new tires and the damages fixed. Keystone will recommend nothing else except the Towmax Tire King 235/80-R16s that were originally provided. Our Tire Shield policy which covered everything for the first blowout in January, now says no, as the tires are inferior. The Tire Minder sensors which notified of a problem AFTER the first blowout at Brunswick, and the second incident the sensor blew off with the tire shreds, we are now told we should have had a booster. People in the campground are giving us advice on upgrading to a G rated tire and I have gotten prices from Goodyear. However, reading this morning in various forums other brands and information about them has been provided. So now I will search out those brands. Staying here until all is fixed.