Hey bro, welcome to the forums...
Your questions have all been answered before in various parts of the forums, so I would suggest utilizing the search feature as well.
As for another angle to answer some of the suspension questions:
Do you have welding, cutting and fabbing tools/experience? If so, then your already ahead of the game.
First things first, do your suspension wether it is a straight axle conversion or just going with the t bar crank and UCA's. The reason I say this (and I speak from experience) is that if you decide to do a motor swap (especially if your going to a 4.3) then you will need to be sure that the new motor's oil pan and accessories will clear the stock suspension.
I have experienced both the IFS (and its problems) and gone to the other end with a solid axle conversion as well as many others on this site. I would strongly suggest that you make sure and have all of your ducks in a row and your research complete before diving in, as (again I speak from experience) it can get VERY expensive if you have to go back and change something mid stride.
Best of luck to you, and for the love of all things right take some pictures of your rig!!