NB: We wrote the WMUK v1 objectives to be clearly charitable but allow us considerable leeway within that.
That's definitely the route I would recommend. Obviously, we have no choice but the make them charitable, but there is no reason to restrict ourselves more than is necessary. I would suggest a combination of specific objects (possibly referencing the Wikimedia projects, although maybe not the foundation itself, certainly not anything that would give the foundation power to change our objects - I very much doubt that would be legal) and more general ones. The specific objects outline what we actually intend to do while the more general ones make sure we can do other things as well if we want to in the future.