I am interested in purchasing the Ez-Bv4 controller. I was wondering if you could use this controller with two wheel chair motors?
No - that product is really for servo motors. You need a DC motor controller.
You can use it to send signals to a DC motor controller, but it cannot provide enough current to power a large motor directly.
We suggest taking a look at this article: How to Make a Robot – Lesson 5: Choosing a Motor Controller