Need help

Basically I have a 2000 Dodge Dakota. The transmission is about to go and the motor needs work. I figured if I'm going to put money into it I'm going to Frankenstein the shit out of it. That being said I have a 2000 Dodge Dakota 2 wheel drive with the 3.9 mag. I want to know if I can swap it for a 5.2 or the 5.9, and or will it bolt straight up. Want to know what all is needed. From the motor to the transmission to the wire harnesses and radiator. Any advice would be great . Never built a Dodge like this before. Just know it's been a good truck and I don't want to get rid of it.