That whiteboard paint might be nice for at least 1 wall. Would be good since you could have a projector project directly on the white surface without the need for a screen, and then can make annotations directly on an image that you are projecting. We have some dry-erase overlays on top of big LCD’s (for when you need to show an existing product, model, or 3D database and don’t want to print it).
Some regular magnetic white boards would probably be good as well along with some good old fashioned pinboards for pinups.
We have the same thing here which we use primarily for brainstorming or small meetings.