Given these dimensions, you'd have a considerably easier time finding much smaller lengths and doing it end grain up--end grain butcher block has superior longevity. Lengths could be a little longer than however thick you want it and reduced post glue up for flattening. Would just take longer for glue up.
*I'm ASSuMEing your planning to glue face grain to face grain along the 7' length given your request for 7' boards.