In Britain I doubt you will have much luck in flying a longwing on rabbit, brown hares. I know of two people who have "dabbled" with home bred female gyr/peregrine & gyr/saker on September brown hares, the decks soon get smashed up and I would say for the time, effort envolved dont really justify the rewards from what I observed.
Stick to Gos, Redtail, harris for all round rabbit & hare hawks in the UK