MeadHall is medium expensive -- it's all about the beer and which one you order. They have an upstairs area where they will rope off a section -- or open up a private room. So, potentially a good choice.
Champions at the Marriott has no character at all (and mediocre food but some decent beers); however, they do have a small outside area and will allow you to cordon off a small section for a group.
Firebrand Saints has a decent outside area. As does Commonwealth. Those will be a step up in class from Champions and food-wise from Mead Hall.