2003 Nissan Pathfinder Engine Swap

I have a 2003 Nissan Pathfinder SE, 3.5L V6, RWD, automatic, and 4WD. I heard from someone today that a Tundra motor will fit into my Pathfinder. It got me thinking, and am curious as to which motors would be best if I decide to swap? It has 205,xxx miles on it now. Transmission has been rebuilt, but I have a feeling the engine won’t last me much longer. I also use it to tow a 2,800 lb. camper. If I could get some extra power, to help with towing uphill, that would be great. Should I get the same engine, and make upgrades to add power? Is adding power for this even possible or reasonably? Or should I get a larger engine with more power? Like a V8? But I’ve heard changing from a V6 to a V8 can create more complications than keeping with a V6. I’d like to keep the swap as simple as possible, when coming to the fit. I don’t know much at all about swapping engines. Besides the fact that’s it’s not an easy job for someone like me, who doesn’t have the proper tools, and who only knows how to do little jobs, like oil changes, fuel pumps, radiators, breaks, oxygen sensors, those small things, you get the gist. I’ll be having someone else do it, if I decide it’s what I want to do. I could use all the advice I can get. Thank you in advance!!