I think a party of four bards would give very nice roleplaying opportunities. Each playing a different instrument of course. And you will have to create a thread in the Suggestions & Feedback forum clamouring for Larian to add bass guitars. But then you can go all out: have a party of two men and two women and call them Agnetha, Björn, Benny and Anni-Frid. Or have four long haired blokes that like to dress similarly. Or have all four of them covered in tattoos and dressed in leather. Or be a high elven hippy group in robes, spreading love and harmony throughout the land, killing no-one and eating only vegetarian food.
