Okay, hate to be the pessimist, but (you know the J-Lo sized one too) Its a hell of a lot more work then you think it is. Finding room under the hood to do would be a nightmare. Using a method of dividing the turbos to two cylinders ISNT really a good idea. Realize that your cutting the exhaust flow down, so you´ll get BAD lag, and re working the intake manifold is more then a ecu reprogram. I think the worst part of seperating the turbo´s is sequencing. Remember the GT fires 1,3,4,2 (I think) Either way its not going to obtain a desirable flowrate.
A sequential turbo set up would be more efficient with low displacement, however, once again finding room under the hood wouldn´t be fun. Even if you used a really small T25 (motorcycle turbo) to spool like a T3/T4 hybrid, you´re still not going to hit the sweet spot in terms of rpms of the turbine without a ton of work. A T3/T4 hybrid is most efficient (thinking of a Garrett) like around 18-26psi. I´m not saying you couldn´t find a great mate between too turbo´s, but I am saying that I really dont think its worth the work. If you used a VJ23 ballbearing turbo and built the scort able to push 14-20psi most of us would be too scared to drive the thing.