IMO, the KB 6lb kit is $3600, do that now (or whenever you can get $1100) and in the future when you can save up another $1200 or so, get the intercooler upgrade. plenum/cai/exhaust/whatever doesn't even come close to worth it on these cars.
KB also notes that the stock gears work great with their blower, and the optimal gear is probably 3.73's