why didnt you opt for a gt to begin with? Insurance and gas mileage is hardly any different. You will probably have to run 91+ octane now with the supercharger.
I have seen a roots type supercharger on a V6. It put down 279 rwhp....It was pretty neat.
Whatever YOU decide, it will have to be a complete custom job.....big $$$$$
Vortech and Procharger both make kits for v6 mustangs up to 08 or 09 so I would think that the 2010 version wouldn't bee too far off. You could probably even use the 09 kits with little or no modification, granted I don't know the difference between the 09 and 2010 v6 mustang.
The supercharger kit would definitely be easier to install than a turbo kit as well.
Turbo is free HP, so you would put down a little more power with the turbo, Only problem is I don't know of anyone that makes a kit. You could do a google search I am sure someone has a kit out there for the 08-09 v6 mustang.
If you go supercharger I would look at the pro-charger kit! Let us know how it turns out.
Vortech/Paxton makes a kit for the V6. Takes the V6 up to about 350 flywheel hp (up from 210 flywheel hp from the factory). Very affordable kit that's easy to install.