Assuming that you will have the normal amount of side dishes/salads/dessert, etc. That's probably too much meat, as you're currently planning a full pound per person (pre-cooked). Two boneless legs should be enough.
I like to keep it simple - make a paste of olive oil, fresh rosemary, crushed garlic cloves and S&P (maybe some purple crack if you have it). Rub the legs generously with it, both inside and out. Tie up the legs with good butcher's twine. Cook direct on the main grate @ 350F until an IT of 130F (lamb should be cooked no more than medium, IMHO). For lamb, I like to use a combo of oak and apple woods for smoke.
Good luck and post pics of the big Bunny Day cook!