SP, we have indeed looked at the LVT-2/LVT-4 as a possible project.
This is going to be a very big kit because of the vehicle size. There are at least 4 variants we can do:
1) The basic LVT-2 / LVT-4
2) The LVT-(A)1 "Alligator"- with M3A1 37mm gun turret
3) The LVT-(A)2 "Saipan"
4) The LVT-(A)4 - with M8 Scott howitzer turret
If we were to proceed with this project, we have not decided which one to do yet.
The LVT-2 seems to be a better choice because it started from 1942 till the end of the war, whereas LVT-4 began production in 1943.
Still need some research...