I wish i would have addressed this question back when my car was at your mod level....
Where do you want the car to be? Point is, say you want a turbo. Then there's no point in getting gears now...when u might have to change them again later.
Decide where you want to go with the car. Then make decisions so you dont double back on yourself. GT40P heads are a nice cheap improvement if you can install them yourself. Gears are always a plus(although i have a t5 and went 3.73...wonder if i should did 3.90s or even 4.10s)
Or save it and look for a cheap blower on the classifieds. Lots of things add power(nitrous) but it doesnt really matter if it doesnt match your goals.
Set your goals straight, then come back and ask something like " i want my car to be ________ in 2-3 years. What should i do now to help get there".
Otherwise you're gonna get a lot of different answers cause there are a lot of "options" for more power.