I recently upgraded the 3 blade to a 50.
I am using a KSJ 50 competition muffler with good results. Good mind you, not great.
So, I got a hyper and have a Hatori SB-5RS and a Funtech 50 muffler to try out.
I will run both of them, although I have a feeling that the hatori is going to cause problems with clearing the fuel tank. The Funtech clears the tank with no problems. I expect both to have very good power.
The only other choice that I would suggest to you would be the MP2. I have the high ratio pipe on my Voyager 50 and that thing rocks with the hyper engine.