Take the kind of event into account when shopping around for your banquet room. For example, an event that consists primarily of the meal itself requires just enough room to sit everyone; a celebratory event like a mitzvah or a wedding reception requires room for dancing.
An event coordinator, such as a wedding planner, can be a lifesaver when it comes to finding a banquet room for your event. If you're working with such a person, just have the responsibility over to them; they have contact that'll make finding everything easier.