More time is needed to evaluate this line of thinking...
Boy-I hear you.
I try and get trucks built the way I currently want and then hold for a few years. That takes the stress out of constant major projects. Build, then enjoy and just tinker around the edges.
You need to decide early where you want to end up, and then focus on the end product, not the intermediate steps. It's also hard to know what your future self will want.
When I first built my 40 (roughly 1999) I wheeled the resulting truck almost unchanged until 2006. Then I did a spring over and wheeled the resulting truck for 3 years, almost unchanged. Then I spring overed my 60 and basically have not worked on it for 2 years. Next year I'm going to start on the 40 again (or sell it!) You get the idea.
But that body is bad and needs to go.
How hard do you want to wheel? If you, want to wheel every weekend, taking every hard line, risking a rollover each time out, then keep the body you have. Realize the life of your truck will be short, but fun. That's OK, you can build another. Or better yet, get an FJ40 with a good roll cage and build that.
If, on the other hand, you want to continue to wheel your truck for years and years, then build it better and less annoying-in your case that might involve a new body. If you want that nice new body to live-you'll need to slow down with a Toybox or other major gear reduction.
You learn as you go, and what you like now will be different than what you want in 5 years.
It is extremely helpful to have more than 1 Land Cruiser. Buy a decent 80. Don't build it beyond suspension. That will take the pressure off your Fj60 and you can do what you want when you want. When you decide to go to Moab next year, you'll thank me.
If I had it to do all do over again, I'd start my 60 project with an FJ62. Just food for thought.