mate whether u like it or not when u start putting more power into gtrs a twin plate clutch is almost a necesity.
From everything ive read and from my own personal experience you cant got past a Nismo super copermix twin plate clutch.
ive got the competition model one in my car and its only fractionaly heavier than stock and realy simple to use.
has stood up to 427kw and still going strong being driven every day.
As for the turbos, get a good set of dump pipes while you have the turbos out of the car for that little bit of extra power