How much do you want to spend / how long until you want to drive it?

It is going to be extremely tough to keep the 8 lug and move to IFS... there are options to change it to IFS with 5 lugs, but even those you will be looking at customizing somewhat because of your framerails.

If you do go with a larger crossmember like you are looking at, you will run into the problem with your wheels sticking out extremely far beyond your fenders as the 3/4 and 1 ton frame rails are farther out then the 1/2 tons and even those have issues with some of the options out there.

Good luck!