The hard part of the discussion is that so many factors go into pitch, based on a piped 61x
a 14/18.5 straight cut small hub is similar range to a 13/17 small hub swirl, then you get into the large hub and you are gonna be 10/16ish.
If you are lighter you may want to go up a size, and obviously the higher you go the less pop you will have. The hull design runs out of legs in the 40's and impeller aint gonna change that much. For bouys and rough water that top speed is fine, but on a smooth lake, it feels kinda slow.
I have multiple impellers for sale if you want one. but you may take a look at whats in there now.