On a Cocker you have a LPR on the front which adjusts the cocking preassure...sis under the Ram..get a Twister coz they work and look nice,,,or get an Evo Lpr coz that what Nexus use...tho they arent that much better...
If its the secondary reg your on about (after your airsystem) then Black Magics are good, MacDev conquests are also good I believe...mind you...some say that "everybody" gets rid of the verticle LPR and just sets the maxflow to 400 psi output...of course, that person then sells you a box of paint that turns out to be a steaming pile of ****e..so, best not believe him..
Oh..and buy from Planet if its cocker stuff..or Just paintball (click on the yellow banner) if its something else...or just Planet really...omg as its not Smart Parts coz there ****e...allegedly