Most MMOs have 5-6 man parties outside of raids or instances.
@OP, check out ArcheAge. It should be going into beta within the next month or so.
7 is such a large number for a party that isn't doing a dungeon. with 7 you can't play any mobas
only thing i can suggest is probably an FPS. none of the new mmos out right now are very appealing to be honest.