I would like to use this vehicle as a daily driver, comfortable off roader, and family troop carrier. It will never be put into serious rocks or twisty stuff, so... I am considering IFS. Originally, I thought about just building a chassis and incorporating 4Runner or LC a-arms and steering, but re-engineering that into a 62 is probably not something I have time to do.
However, I came across a FJC complete chassis/drivetrain for sale, even down to the tires. It has everything below the body line (fuel tank, front diff, arms, rear axle with e-locker, etc.). Looks like the FJC is about 1.6" shorter wheelbase. Stretching looks to be super easy on that one. It's also a little wider (~4") than the 62, which would be nice.
Here's the cool part. The front diff is driver's drop, which means the GM GenV L89 and 10-speed trans is back in play using a Jeep JK Rubicon transfer case (4:10).
I am not concerned about the amount fabrication needed unless it means getting into the body of the 62. I don't want to mess with OEM FJ62 sheet metal too much.
Just V8 swap the 62 and put a Dobinson's MMR kit on it. 10% the effort and 96% of the result. It sounds like you don't actually have time for what you are describing at all