What kind of stuff do you want to do? what is your plan for the truck, and if I had 3k to spend at one time it would be either SAS, or front and rear lockers, and if you dont want to play in big rocks than yes I would do the lockers. I look at it this way, you can have the best tires in the world but with an open diff as soon as one of thoes tires looses traction they are pointless, where as with the locker you still have traction on the other tire to push you through.

All of the other stuff you can aquire as the need presents itself. But first you need to decide what you the truck to do. The single most effective mod that you can do is traction control, if you dont have traction you will not go anyware.

Are you looking for mods that will get you down the trail? or are you looking for the mods that will look the best when you are at the mall?

All that being said I do not have lockers because at this time I cannot justify them.