i also asked a question similar to this one and someone told me to sell my bike because its and expensive hobby
i didnt listen but from what i seen the only things that stood out to me that people recomended is your not really gonna get more power out of this bike unless your a balla and put turbo or nos
Lightening the bike is the best mod. It improves handling, acceleration, braking, and will even cook breakfast for you.
Once you get this bike set up properly though, modern 600s will not be an issue in any contest of acceleration. As is, a stock zx7r is 100 lbs over the weight of modern bikes. In other words, you are carrying around the equivalent of a passenger.