AMS / AV + would almost certainly be easier
than STV, which would require huge constituencies for
rural areas (and even under FPTP, there are inequalities
in constituency membership because of the difficulties caused by excessive size), but then a whole new can of worms would be opened up concerning how to set the ratio between corrective «top - up» MPs, and constituency MPs, plus a whole load of other factors such as whether to allow dual standing, whether the two votes should be two
choices or interconnected, whether the list should be open or closed, etc., etc..
Vouchers don't provide an actual
choice for students living
in rural areas who have few, if any, access points to schools other
than their local public schools.