Somebody has done a dual supercharger setup on a T-bird already so it's definately do able. That is IF you can find room for two superchargers, and IF you wanted to waste money on such a setup. Personally i dont see why you'd want to do that because you could just as well buy one really good supercharger or turbo kit for the same price (cheaper actually) as two 6psi superchargers. You would also have to run two superchargers which would take alot of power away from the combo so i believe running one high psi supercharger would make more overall power than two smaller ones.
Besides that, they dont sell that intake or that car so this is all for nothing...LOL