This is pretty much the route I'd recommend to you as well. Maybe a hot side intercooler tube and a downpipe as well for some added EGT reduction.
With that budget you're probably just short of a tranny build, which would unlock the true potential of the truck and let you get up into the 500hp range easily with some good EFI Live tuning.
But with the stock transmission you're still able to do a pretty decent amount of upgrades and have a much better performing truck.
Other things I would add to that list would be HD tie rods and idler/pitman arm braces. That will give you a very sturdy front end capable of handling all that power in 4x4.
If you'd like to talk over some options and a nice package price, I'd be more than happy to help. Just let me know if I can do anything for you