http://www.proturbosystems.net/

I sent them an email:

"Do you plan on making a turbo kit for the '05+ Mustang GTs?"

Here is their response:
"We are looking to do a package in the future. We would need a donor car first.

Thanks, Dalton Campbell
Pro Turbo Systems.LLC
210-657-2076"

Here's their contact information...
Pro Turbo Systems
4850 Whirlwind Drive
San Antonio, TX 78217
Phone: (210)657-2076
Fax: (210)599-4507
M-F 8am-5pm CST

Just figured i'd post this in case anyone might be interested. I emailed a few other companies as well regarding turbo systems.