You'll probably run into a host of fitment challenges above and beyond those you already mentioned. Probably have to mod the shifter, mounts, wiring, exhaust and who knows what else. Could be a fun project if you are up for the task.
Man, I love my 2002 Truck. But it would be great to have a modern 6 speed or even an 8 speed transmission. the 3.4L engine is solid and would be a good match for a better transmission. Seems like a good business opportunity now that I think on it.