|I have another option that will get your desired effect, but that does not involve changing your prop - change the way you handle your throttle.
All props "walk" to one side, particularly in reverse when starting from stationary (a 27 stern swings to port in reverse). The way to avoid this is to get some way on the boat and some flow over the rudder so it is effective in counteracting the swing. (3-blade props have the reputation of being less prone to walk, not because they are inherently less prone to it, but because even at low revs, their far greater blade area and consequent thrust gets the boat moving more quickly and the rudder working more effectively, before the stern starts to walk.)
Instead of putting the engine in gear and easing on the throttle, shift into reverse and give the engine a shot of power; in other words, rather than accelerating from idle to 1,000 rpm, run up to 1,500 or so, but just until the boat begins to move. At that point, drop back to a point midway between 1,500 and idle. That little shot of power will give you enough motion to allow your rudder to bite, and if you give your rudder a touch of starboard helm to counteract residual walk, you'll exit your slip straight as a die.
Do something similar when stopping - rather than easing into reverse, shift and give the engine a good shot of power. That burst of reverse thrust will stop the boat reliably and quickly enough that there is no time for prop-walk.
After I saw someone handling a boat this way, I took out a C&C 34 (with a Martec folder, a worst-case combo) and practised around a plastic buoy (so I could run into it with impunity). In short order I could put that boat anywhere I wanted. It wasn't difficult - in fact it was fun - and since then, I've had no qualms about putting Towser or any other boat anywhere.
C&C 27 Mk IV