We've been rolling this idea around lately. I'd like to see a properly executed twin turbo setup on one of these cars, however, that really means lowering the compression in the engine so that you can run some meaningful boost. I'd really like to see this done on an LN sleeved block, with uprated connecting rods so that we can be very confident it won't blow up. Can you probably get by on a 3.2, since it does have the thickest sleeve thickness? Probably, but I'm still not sure I'd want to push that. Either way, you're going to need lower compression pistons to do it right, and if the motor is apart, I'd just as soon sleeve it with LN sleeves.
Next comes the topic of where to put the intercooler. I'm sorry, but I don't buy the idea of removing the chassis bracing plate and putting the intercooler there with the core lined up vertically so that it's only relying on convection cooling as there really isn't any air being moved through the core, plus the fact that you simply can't fit a very large core there and the loss of structural integrity by removing that plate.
We've got a set of 2.7 case halves laying around that need to be sleeved (suffered sleeve failure), in which case it will become a 2.9, and we're debating having JE make up 8.5-9.0 pistons for it. If things go this way, the car will get a pair of turbos, and either air/water intercoolers or a giant air/air unit mounted where the rear trunk used to be.
We'll see what fun the future may hold