The pressure calculator at zipp.com is the best I've found. I just put Pirelli p zero 30mm tires on zipp 303s hookless wheels. For my weight, 52/56 psi was suggested. With 19mm internal width hooked rims and 28mm tires it suggests 62/66.
Don't cheap out on the rim tape. Some use scotch 8896 tape, if you can find it in the right width.