A new offering from HKS. GT Supercharger System: GTS8550 Complete Kit. A PDF that had a 7/25/2011 date was on the internet yesterday. According to their performance graph it should add around 70HP.
Factory ECU is retained with no mods. Average installation time is approx. 22hrs.
Model USF40, Engine 1UR-FSE, Code 12001-AT005.
They did not have a price; but similar BMW M3 was priced at $4500.
People do it on the ISF so I don't see why the LS would be an issue. I've had nitrous setups on a few cars. There aren't really any options for make an LS quicker. There aren't any aftermarket intake systems for the car either. Only performance mods I have done are some Tom's racing braces, wheels, Brembo BBK, Tanabe springs, and Joe Z axle back exhaust.
I feel you on that... Seems the more I search the less I find on this Model, I found a 50 shot kit, but I'll hate to start drilling into the manifold.. I'll admit, my baby is quick already... I just want to shock'um at the light when I pull away!!!
It's not cheap, last time I saw it was about 18k, and it's not going to give you crazy amount of power either. Not sure if they have a version that works with the usdm ecu, so you might have to make some custom stuff for that. The LS isn't really a "performance" type of car, so you won't find very much in that department.