manual valves and cans

i just picked up my cylinders from a friend for my crx, i want to just run a basic front/back manual valve setup on my car, that way there is less stuff to break. just up and down to hammer it on the ground not to play w/. i was just wonderin how its gonna work and how many people have done it. my cans are 3.25, also... how much psi? and what size line? thanks for the help