I am not sure what circuitry is on the motor shield
(I usually use my own boards (www,wiblocks.com) 
You will probably have a dozen or so transistors, resistors and connectors.
If the motor shield provides you a way to easily replace these parts it
could save you some of time. You could always start with a few motors (and
transistors) and see how it goes.
(* jcl *)