In short, randal and paris trucks are pretty similar, but there are some differences. paris' use a better way of gravity casting and are generally known to have a nicer bushing seat, but randal has more variation in BP angles (35,42 and 50). randall's are also the industry benchmark for truck standards.
bear trucks on the other hand are meh. their shoddy casting has only slightly improved over the years, and i would ride randals over them any day.
^^^ common fracture point
If you're going for a drop carve, fuck RKP's and get a good oll' set of Indy-Hybrids. these will blow your fucking mind. you will be on a mega low fucking magic carpet and since they increase your wheelbase slightly, you will get a more flexy fun ride for cruising and absorbing the bumps.
finally, ditch the 4prez and get some abec 11 flashbacks or gumballs. better value and ride imo.