[al83s]

Here are some of my ideas on the weight loss (some already done, some on the way):
Lose spare tire and tools
Stock exhaust is really heavy, how about a spec-like stock header-custom cat bypass-magnaflow race muffler setup.
Lose the stock seats in favor of some manually adjustable or fixed-back race seats+5-point belts
Lightweight wheels (I saw a 500awhp 997tt pick up ~20 whp by switching from stock rims to a set of really light Dymags)
Lose the airbags all around and install a momo wheel (not for everybody, but I dont mind)
some light-weight battery (kinda expensive)

That would give you several hundreed punds, without sacrificing too much comfort.
If you want to go further - lose stereo and speakers, AC/heater, gut doors, lose trunk carpeting and all the sound insulation, CF hood/trunk, interior carpet, lose the convertible top etc. etc.

Regarding the rest of the mods, stock breaks + race pads should be enough, +1 on m030 or PSS9+ stiffer sway-bars.
It is very expensive to make your car equally fast in a straight line to a corvette, that just wasn't the point. . . I am playing with the idea of a turbo kit or a 3.6 transplant myself in a few years.
Good Luck with your car, Im sure you will enjoy it.