You need a speed controler like this
http://www.giantcod.co.uk/hobbywing-pen ... -p-41.html
To power the brushless motor, and horizontal or vertical is up to you, horizontal means the chassis (frame) is smaller, and flatter, where as having it verticle is harder to make and mount, but has the advantage of being able to flip robots over also (if your having it spinning so it spins upwards)