(Using PS3 Controller) Direction keys could be used up and down for tools, and sideways for brick selection, and the paint can could be activated whenever you press down one of the brown townogs. Jump would be X, R1 would be to fire weapon/tool. L1 would be jet or right click. Start would be the escape, select could be your brick menu, Square to place a brick once the ghost brick is down, L2 is to move the brick up, and R2 is to move it down, directional keys would be used to move the brick around once a ghost brick is down, and Circle would be to crouch, Triangle could toggle walking.
Please tell me if I left anything out?
Custom GUIs would be a problem with this though.