Very cool project!
I'd build on a cobra chassis personally. This guy in SA is building on a cobra chassis with a 1uz toyota v8
http://www.madmechanics.com/forum/bu...a-project.html
Engine options- I'd consider inline 6 options too. Toyota 1jz or 2jz, datsun l series, Nissan rb series, bmw m and s series.
You would have a time fitting a jag v12 in there, trust me!