Front yard landscaping - what width/height boxed hedges?

Does choosing the size and height of boxed hedges have anything to do with the size of the house? If we match the width of our path to that of our front doors, we will have 1.1m for the hedge. What height and width boxed hedges (when fully grown) should we aim for?

We plan on doing a front fence, should the hedge match the height of the fence pillars?

PS. I'd still love to hear your thoughts on my Entrance dilemma :)

B