I've got 20" wheels so similar to the ones you want to buy. I'm wondering if they're made by the same manufacturer with different names depending on vendor. Anyway, the tires I have are Yokohama Parada's Spec-X 265/50-20 and they just fit with no clearance problems. Only had to tweak the torsion bars a few turns for clearance. NO cladding interferance at all.
I noticed you were looking at 55-series tires. With the 275 width and the tallness of the 55's I believe you WILL run into problems with cladding for sure! Hope that helps in your decision. By the way, I love the Parada's. Scott