depends on goals and current setup- most twin setups will put out around 350 to the wheels on an otherwise stock splitport 3.8, a 200hp increase from stock. but factors such as single/splitport change that number.
It can be expensive though- new the kits are quite pricey, and the power can easily be reached with a single turbo.
this is an opinion. but anyways if you plan on having the v6 for a while i would say go with it. v6s can easily be made to blow v8s out of the water if you are willing to put that much money into it
if you want any turbo set-up for your V6 go to www.tmaturbo.com all they do is turbos for V6's. their twin setup is most efficient between the 450-800 rwhp range on a stock motor and throws down an 11 second 1/4 mile.
I agree... You can dress up a V6 and do all the mods you want and make it perform better than a GT. I have an 09 V6 and am on my way to that but I find myself saying, "Why dont I swap my ride for an 05 GT?"