I suggest that you put the trans brake button on the steering wheel like most of the other cars. Just because you are using a hand brake does not change the way that a trans brake works. You would stage the car, while holding back on the brake handle, press the trans brake button, let go of the brake handle, watch the tree and prepare to launch the car. A foot button would work but I believe your thumb reaction is quicker then your foot reaction and therefore would give you a quicker and more consistent reaction times.
I just got my King Chassis FED last weekend and I have to admit that I also sat in mine and made engine noises. I am also running a hand brake. It will be a blown alcohol injected 427 big block. Good luck on your build.