shortening the chassis? help

I am possibly starting a custom build project (a two seater convertible), and the car that i have decided to use is the Jaguar XJS V12 convertible,
As i require a shorter wheel base it will be a two seater, not 2+2 as the XJS is, the car will have to be butchered. The over hang may also be shorten, but that is an easier job.
If jag dont give us the f-type im gonna have to do it myself!!

And the questions are as follows:

Would this job have to be prosfessionally done?
Will the car be structurally dangerous after?
( I have heard many horror cut&shut stories)
Can it be done at home with the right equipement?
(And what might they be?)
What changes have to made to the drivetrain? (drive-shaft shortening?)
Would this pass the SVA test? (In the UK)

I am very inexperienced with jobs of this magnitude, i'd love to meet someone who has done a similar job.

PS any recommended books or videos as guides to a such job would be highly appreciated.

regards Cerbera