I believe that by exotic particles they don't mean particles that are rarely encountered. They mean particles that have physical properties that have never been observed or even predicted by theory. I think we'll have a tough time looking for some of these.
Anyway, the energy requirements are the least of the warp drive problems. We need to solve the time travel problem first. Until we have, we can as well try to use a perpetuum mobile device to get the energy – it's not as impossible in comparison. Breaking the second law of thermodynamics seems to be an easier target than breaking causality, because it has less implications. And a more important target, because if we don't break it we're fucked.