You're going to have problems getting that across the border (although there are creative and
slightly illegal ways of doing it ....

). Better to look for an older version. Once they're 25 years old, they can be brought in with no conversion.
The Integrale is a fantastic car and on my short list. A true homologation special. Take a look here:
http://rgruppe.blogspot.com/2008/08/gruppe-b-saturday.html