Unfinished GTM

Looking to purchase unfinished Factory Five.

GTM.

I would prefer to finish the build,

I want to build a "driver" so a small block, or no engine is desired so I can slide in a V12, unsure of fitting but photos and posts show it will fit
Considered a GT40 but it so tightly coupled with Ford V8s it would be a losing proposition to do a V12 swap.
Considered SLC but forums suggest QC problems
Any suggestions on a V12 mid engine kit car? I know that a 2 V12 transplant were done on a Lotus but can't find any trace of them ir how it was done.