Instead of a huge lump of american iron, how about that nice '60's buick cast-off that we adopted as our own, the aluminimum Rover V8 ?? It weighs less than an iron 4 pot, has good tuning potential, and is already available in a Seven style car fully SVA'd (that's a UK type approval for low volume specialist car manufacturers).
http://www.westfield-sportscars.co.uk/SEiGHT-kitcar.htm
I wouldn't want to look up at the front step of a <insert semi-truck vendor name here> though.......