The things are you are talking about will be ahrd to pull of on the budget you are giving us. No offense but once you start engine/trans or tcase swaps one thing leads to another cost wise. Then there are bigger axles to handle tires size, etc! Check out my build...
Absolutely nothing special and nothing compared to my last rig on tons and 42s, but it will be fun, I will beat the hell out of it, fix what breaks, and I have less than $4k in everything including the jeep. Other than a few things on the d30, it will be dead reliable and I will upgrade as needed.
Also, swapping in a straight 6, done right, is not going to be cheap at all. Everything is different than a 4cyl.