Do you have a specific budget in mind? The body lift, plus install (unless you do it yourself) you're probably looking about 1,200 total. The body lift is going to do just what the name says, lift the body, off the frame.
The suspension lift, is going to modify the actual suspension, and "upgrade it" New shocks, coils, etc.
As far as brands for the two
body lift: Performance Accessories has EVERYTHING you need in their kits. Rubber Frog has videos on here going over the basics for the install.
suspension lift: I am personally a HUGE fan of Zone Off Road. They are the sister company to BDS suspension. Their customer service is great, their products are prices very reasonable, and in fact, the cost difference between their 4 and 6" kit really isn't that much.
Cost to install the suspension lift will be more than the body lift, as it is more involved, and will require an alignment when it's all said and done.
So, if you are just trying to accommodate larger tires, and don't want to spend an arm and a leg...go with the body lift. If you're more concerned about clearance, and articulation ability, go with the suspension lift.
Another option, do the body lift, and a leveling kit.