Reverse scrolling sideways only possible?

Just bought a new 11" Air and have a question regarding the Reverse Scrolling option.
I'd like to be able to have normal up/down scrolling (e.g. Safari & Pages) to be normal but the sideways multitouch gestures (switching between spaces) to be reversed so that they act like multitouch on an iPad.

Does anybody know if there is a way to change this?