First, I want to point out that it is your truck and you have to build it in a way that you are happy and fits in your budget.
You need to look at your long term goals for your truck, I have been modifying cars and trucks for over 15 years and in that time I have seen a lot of people waste a lot of money on aftermarket parts and accessories that they just changed out later. It is much better to have a goal and work towards it.
I want to clear 35's: Go here: http://www.ramforumz.com/showthread.php?t=168422
I want to look like the baddest redneck around
6" lift + spacers/body lift, duel cb antennas, 35 or 37" tires on 20" wheels exhaust.
I want to trail/crawl my truck
Beginner: mild lift, off road tires, CB radio, recovery hooks
Intermediate: bigger lift, bigger tires (clearance)
Advanced: keep your truck stock for towing your trail rig and buy something narrow and modifiable like a TJ/YJ, Sidekick, or even a Cherokee and specific build that.
This way, you can buy components specifically aimed towards your goal. You will always know what to get next, even if it is just spare parts.
With that being said I will give you my opinion.
Don't do a body lift. Seriously, it is a pain in the ass to install, it looks like a body lift and quite frankly it is not as good.
There is a time and a place for a body lift, and I don't think its the best time and place.
Body lifts have a low initial investment (less than $500), but there are a lot of soft costs that you need to consider too:
1. With your current set-up and the body lift you will need to extend brake lines
Fix = $100? in brake lines
2. How are your suspension and drive line angles?
Fix = premature ware on everything un-sprung. (read ball joints, end links, bushings, tires, shocks)
Why, in 2 months you will want 6, in fact it sounds like you are stoked at the sound of 5" The price difference between 4" and 6" is not a lot.
BDS or Procomp
Comes with everything
I know Rough Country has kits (4" and 6") for less than $1000 but If it was my money I would spend more on the BDS or ProComp.
Hope that helps.