Hello Steve, from what I can see your truck looks to be in great shape with no rust. I like your ideas for it.
There are many different ways to achieve what you want and I suggest that you start with checking out the Gallery and seeing what others have done. For instance there is member by the name of "Weeds" that has a AD Suburban that he grafted the front suspension from a 1/2 ton pickup. Others will buy a manufactured IFS from one of the vendors. Yet, others chose to mount the cab on a newer chassis such as an S10.
Grab your tape measure, start planning and then decide which way is best for you and your skills. If you decide to re-purpose a suspension from another vehicle you may need to buy a donor vehicle for parts.
No matter which you decide to do, we are here to help.
John