As the performance potential is so low, I run inexpensive 3 blade alum. props on ours and stuff I work on. Solas or stock Honda OEM both work fine.
With winter coming up, you might save a few bucks having your prop repaired to perfection and re-pitched to get you up around 5500, which is where the engines I've worked on (40-90 Honda) seem to like to run.
One of our pontoons is a 24' with a Honda 90. That boat with a 13" pitch prop would run 24-25mph at around 6100. When we switched to a 15" prop, we picked up a mile an hour, and rpms dropped to 5500. At 6100 the engine had fantastic throttle response, but sounds pretty busy. At 5500 we get similar throttle response, just a hair slower getting to top speed, still plenty good enough for tubing, and the engine sounds great.
I bought the 15" prop as a NOS Honda part on ebay for 45.00. Likely came from a dealer going out of business....
