What all will fit?

The 5.9 and 4.7 are two totally different animals. Front accessory drives are specific to each. OP says his og engine is a 4.7, let's not get confused on the situation.....

Yep, not saying the accessories from the 4.7 would work on the 5.7, only that the 3.9 accessories in his parts Dakota would work on the 5.9.

At the same time, the electronics for a 5.7 are much closer to a 4.7 than what is on a 5.9. So a 5.7 would be easier to swap and would bolt up to his 45RFE, even though there are things that would still take work.