Marty,
My advice is to try out a 6-footer first, if possible. I know with my L35 (35 hp) gets loaded up when the blade is full of gravel. Maybe you could get a 5.5' model. When I bought mine, they only came in even foot lengths. They were available in 7 & 8 ft. lenghts too. I have the R-3 tires on mine, not the ag lug type, but more of the industrial type. In order to get adequate traction, I put a load of gravel in my FEL bucket. Without the extra weight, it wouldn't work near as well. Please let us know what you decide and how it turns out.