You can bi-wire or shotgun bi-wire with 2-way speakers as well, as long as they offer two sets of binding posts, which many manufacturers do. If you want to tri-wire, that's a different story--then you'll obviously need a 3-way speaker. I'd still say go with the speaker that sounds best to you within your budget regardless of how many drivers there are. Buying a speaker just to be able to bi-wire is like buying a car just to get a certain set of tires--better to go by the performance of the whole package. Best of luck.
Tim