Need advice for a 95 mustang GT

[chickendreamer]

Hi all, I have a 95 mustang GT 5 speed with a few modifications which are 2 chamber flow master muflers, march pulleys, k&n air filter, jet performance chip, stage 1 NOS kit(just need to hook it up) and 3.73 gears. I decided I wanted to give my mustang some more power and I bought a performer rpm intake, and a 70mm throttle body. The question I have is it worth the extra $1000 to get the performer heads from edelbrock or should i spend the money on something else, and also should I change my injectors, or anything else?

Any advice would help, thanks.