Keep g52 or replace

[Thomas f]

Toyota Hilux
Engine : 5L.   Gearbox : G52. 
Hey guys, I have recently rebuilt my 5L motor and found that the input shaft of my g52 is worn where it sits in the spigot bearing. My reverse synchro is also worn out too. The box has been reconditioned at some point(last 100 thousand kms by previous owner). I am planning on doing a lot of touring and lots of long kms. Due to this is it worth putting a taller 5th gear in the g52 and getting the input shaft fixed or would you suggest a different box such as a r151 or w56 for example? I have also just bought a new excedy clutch for the g52 and bolted it onto the flywheel. I have the electronic push button 4wd and would like to keep it if possible. What would be involved in the swap. I believe a bell housing for the r151 would be necessary but can I swap my t case over from the g52 to the r151 or a different box? Would I have to change flywheel and get a new clutch seeing as I just bought a new one?Any help and suggestions would be greatly appreciated