Personally I don't think you need the SS 4 blade. That is a lot of prop for that motor. I am not sure what boat you have but I am a huge fan of the PT's. I have a 30HP Tohatsu 4 Stroke on my Bossman Karma 19. I had it propped with a PT TLR3 12P but it would cavitate to easily. I got a top speed of 34MPH with it but couldn't jump up on plane as easy as I wanted and lost a lot of RPM's in any kind of chop because of cavitation. I recently switched to their SRA3 11P and that is the perfect prop for that motor boat combo. I can jump on plane in nothing, trim the motor up without cavitation. I lost 2 MPH but it was worth the sacrifice in speed.
If you think about getting a new prop call Power Tech they are extremely helpful in picking out the prop and if you don't like it they will exchange it for $50.