Ronin, you are certainly free to do whatever you wish and you should accept the feedback here and on Mad Mechanics as a gift. Most of the guys here are committed to building a project and most of these projects constitute $30k - $70k investments plus many hours engineering most aspects of the build.
I agree with everyone else that replicating a mid or rear engine car with a front engine donor will only lead to a very inaccurate and odd looking creation. The only exception that I've seen to this is the Bugatti build on a Cougar donor that turned out ok. The difference is that that donor didn't have a large front mounted V8 and the Bugatti body isn't as low slung as a Lamborghini. If your main motivation is cost, I'd suggest you find a nice Camaro, Firebird, Corvette or other front engine car with a big engine and put your money into a ground effects kit or body package that maintains that cars look but improves it. A replica build doesn't stop with just throwing a body on a frame, the small details like lights, interior, grills, emblems, paint and bodywork run the bill up very quickly. Reworking sections of a donor can also be very expensive even if you are doing the work yourself. Trying to make a Camaro look like a Lamborghini is like trying to make an elephant look like a lion, no matter how much you trim and pull, the skin will never fit correctly and you lose the overall flow of the design. My advice is that if you are going to try this, build it and prove us wrong instead of talking about it. When done correctly, a stretched Fiero, MR2 or Boxster is much stronger than it was before and the stretch can give you extra room to squeeze in a larger engine or let the stock engine run cooler.
I agree with LamboJayso and wonder why you continue to ask for build support on something everyone has been clearly trying to advise you not to attempt. The purpose of this site is to help builders and dreamers like yourself, however there comes a point that you need to humble yourself, accept the reality that everyone is sharing with you and respect the experience of those providing that feedback.
It's your money, your dream and your car and I'm 100% convinced that the members here are just trying to provide you honest advice to protect you.
Chris