You don't want to do two toons similtanously ... becuase you actullay won't be playing them actually similtanously, you will be looking at one screen or the other, not at both at the same time, and you will eaither be using you right hand or your left hand but not both at the same insant, like the way you type you think you are using both hands but in fact you are using one at a time.

What you really want is one set of controls but the ability to switch between characters almost instantly ... kinda like what I have ...