I think you should make a plan of what you want the truck to eventually be. Then figure what it will cost to get there. Then figure who long it will take and at what pace you want to add things.

Locker is good but if you get one that needs gear setup, down the road when you lift and get bigger tires you will want lower gears and you will have to redo your locker/gears.

If it will be several years before its done then stock size mud tires is a good start. By the time those tires are worn out you will have had time to do things like lift and gears. Then buying biger tires will be a natural progression. Look through the for sale section at all the smallish AT and MT tires. Free is a good price and a good place to start.

Browsing the For Sale section will give you a good idea of what mistakes people have made. Lots of that stuff seemed like a good idea at the time but turned out to be a waste of money. Those people are taking a loss on expensive tires because they didn't plan their build up very well.

I think a winch and bumper is not a bad start but if you decide on a bodylift later the bumper will have to be re-done. Rock sliders are the same way. If there is no possibility of a bodylift in the future then go for bumper(s) winch and/ or sliders.

Whatever you decide on for a first mod, make sure its something that won't have to be re-done later as your truck evolves.