Boy names that begin with P?

I want the name to have 2 middle names... Scratch that... It has to have 2 middle names. The first and middle is Greyson Seth and I need a P names so the initials are GSP, it's a family tradition for the dads initials to be the first sons initials. The only ones I can think of are Pierre, Parker, Peter and paul and those all are taken or I don't like them.