Trans swap 06 Dakota

I have an 06 dodge Dakota with the 4.7 and a 4 speed auto, it’s starting to slip a little and I was looking into possibly switching to the 5 speed auto? Is it worth it? I drive a lot of highway and I tow with it on occasion, basically my two questions 1) is there anything I’d have to change to go from a 4 speed auto to a 5 speed auto 2) do you think I’d be better off or should I just buy a new 4 speed?