We agree with the results of your research--we have never found a load range H version of a Michelin 11R24.5 tire either. (We're had a customer who claims to have purchased such a tire, but we've never seen one.) However, don't despair. We have had excellent experience with the Bridgestone R293 11R24.5 LR-H tire. Readers should keep in mind that this advice does not apply to newer coaches equipped with 315/80 22.5 (low profile) tires. Michelin not only makes the 315 tire in our recommended load range L, but the Michelin tire is the ONLY 315 tire we recommend. Complicated, huh?
I agree with Newell on the Bridgestones, and have also found Toyo tires to be very good. I prefer to use steer tire versus drive tires, as they have a reinforced edge to reduce cupping. It may be just me, but I also think they ride better. I have a 1987 with a tag axle, and just spent the summer in Alaska with no problems.