Ever since driving (and falling in love with) the 2004 GP GT I've kept the idea of a Gen 2 3800 as a possible next vehicle.
The only other "real" local forum for GPs I visit is Ontario/Quebec Club GP http://oqcgp.com (I don't think they are affiliated with glubgp.com). Anyways I've noticed that alot of members with GTPs have been converting to turbos and GT guys are adding on the turbo, getting some awsome power (many running in the 12s).
From what I understand the L36 is actually better suited cause of higher compression ratio. The L67 is better in the long run of course, due to stronger engine/trans.
The kit from Cartuning performance is $3000, but comes with everything including PCM and bolts onto the stock exaust manifolds.
Claims 280hp+ on a stock L36 engine..