I would say it really depends on what irons you have and what loft they are, but in general you want 4 degrees of loft gap minimum. My PW is 46* and AW is 50*, so I have a 54* and a 58* Vokey. You could probably get away with a 56* as your highest lofted wedge if you are a higher handicap like me, I only have a 58* because it gives me a nice gap for full shots from the 54*. I would recommend your highest lofted wedge have a forgiving bounce/grind for bunkers, and maybe get a different grind/bounce for versatility on your other club e.g. one for tight lies.