Sure - theoretically possible, but tuning's a pain. It's called "staged forced induction" and I've seen it on "pull" motors. Think: a Diesel, compressing about 22:1, and getting 5atm (73.5psi) boost!
It's also doable with gasoline engines, but actually harder (with Diesels, all you have to worry about is fuel metering - there's no throttle.) You'll put the turbochargers upstream of the supercharger, so that the turbos feed the blower and you'll compress the forced charge still further.
If I had a run stand lying about - and a whole bunch of dosh - I'd play with the arrangement just to see how far I could push it. I don't know if I could push it all the way to 5atm - but it would be fun to crunch the numbers to see what would come out of the flywheel (and to figure out just how hot the charge air would be - feeding a split turbo arrangment into a large Whipple blower...)
5-90
