You absolutely do not NEED a screw compressor for that press. 5hp with a 60 gallon tank is the smallest any one would recommend you go with a printing press. Once you're up and running you'll see how often your compressor cycles based on job type and number of heads running. I think you'll agree after it's up that you don't need the rotary for those air requirements. The only change I would have made to your choices is going with an 80 gallon vs the 60 gallon tank.