Help: Speakers to fill Exceptionallly Large Room?


I'm trying to outfit a large coffeebar with a decent pair of speakers or monitors on a budget. The room is approximately 20 feet wide by 80 feet deep. My current plan is to place one speaker at the front of the space aiming at the bar and a second about half way through the space, again, aiming at the bar. Everything beyond the second speaker will be a "quiet" space for all intents and purposes.

Rules are that I cant use more than two speakers and they have to be wall mountable. I'd like the place to sound good, though I know it will be no acoustic dream, by far. Price range is probably $500-600, $1000 max. Should be relatively efficient, because I'll need some db's to fill the space. Any help appreciated. Thanks.
jaminsky
I second the Bose 901s. You can hang them from the ceiling with chains and they are efficient and not demanding of the electronics that drive them. They have always worked great in bars and the like.
I can recommend Altec Model 19s. They are large, informal, decent-looking, very efficient, have a long "throw", are dynamic as all get-out, are only somewhat difficult to find, and have good resale value. They can be found in 'beat-up" condition (which will be in your budget) or absolutely mint (which probably won't be), and don't sound tremendously different either way, and can be "restored" from beat-up to OK-looking with a bit of wood-finishing (but one has to be sure the woofers/drivers are OK). They tend to roll off a bit in the treble, and they don't do 20Hz at the bottom end, but for a cafe, that's probably better in both cases.
Bose 901s efficient? News to me but they must have changed during the years. The originals were notorious for their INEFFICIENCY. No surprise as they were based on table radio speakers equalized so that their midrange was suppressed to the level of their treble and bass. Anyone familiar with the response curve of typical small single cone drivers will appreciate what is required to do this.