As long as it runs fine you shouldn't really have to replace anything else. I've got a little over 150k on my truck also and recently did front CV's and bearings. Both CV's had torn boots and one of the front bearings was howling, so I just went ahead and did both sides. I think one of the rear bearings is going out now too, I'm getting some noise.
Maybe think about fluids. Have diff and xfer case fluids ever been changed? How about transmission fluid?
FWIW, timing chain probably doesn't need to be done until 200k at a minimum. The water pump is driven off the serpentine belt and can be replaced separately if it starts to weep. Mine started leaking around 100k so I replaced it. I probably won't even think about doing the timing chain until well after 200k.