[E.D.75GMC]

Unfortunately I won't be able to swap the heads, don't have a big budget. Working part time while I'm in school currently.
Now, I don't really know much about cams. I would be having a good shop do the installs. I know what cams do but I don't know how to judge what is best for my truck. It has the 4.10 rear gears that come with the 3/4 ton so it revs pretty fast. I'm just looking for something relatively mild as the truck is just a driver. Don't know if anyone has any recommendations on a cam and lifter kit? And if I would need rocker arms as well?