The 235/80r22.5 is strictly a Michelin tire size. From what I have read people are going to a 245/75r22.5 tire size so they can find tires from other brands that are comparable in size to the original tires. As for brands, Hankook & toyo are very popular. Stay away from Goodyears as they seem to be having problems, not for everyone but enough that I would not chance them. I went with Sailun tires on our MH and have been very pleased with them. They are available in 255/70r22.5 size, which may be too wide for your rims.
Good luck on your hunt for tires.