What about just purchasing the cabinets in black from Axiom and transfer over the components, it should be a little cheaper than the whole speaker.
So far as removing the vinyl, I have white foil/vinyl wrapped kitchen cabinets, well, doors and drawer fronts, and am in the process of removing it. It peeled off rather easily, especially with a little heat from a heat gun, and left the glue behind. A few hours of sanding and the doors and drawer fronts are nice and smooth. I am in the process of painting them right now. So it is possible to remove vinyl from MDF but it can be labour intensive.
You could try to paint the vinyl as well, there are paints for plastic in a spray can that I have used for some automotive trim and it seems to work very well.
