ok, which ones will sync with the camera at 1/250 or faster?
Flash sync speed is generally a function of the camera's shutter rather than anything specific to the flash. With focal plane shutters (like typical D-SLR's) it's the shortest exposure duration for which both curtains are open simultaneously for at least an instant, permitting the flash to expose the subject. Flash duration is generally much less than the sync speed for hot shoe type flashes, so the camera's sync speed is the limiting factor. That's usually 1/200 or 1/250th sec. for high-end D-SLR's.
Studio flashes/strobes will also have a very short flash duration for reasonably low power levels, like what you'd need for exposing splashes from water dripping into a pan. But flash duration gets longer for higher power outputs; your basic Profoto monster unit may need more like 1/60th sec. at max output to light an auditorium.
Finally, flash sync speed isn't really relevant unless you're trying to expose in bright sunlight. For most indoor/studio shots, lower ambient light levels mean that the flash exposure generally
is the exposure, so you can use any shutter speed you like, as long as it's longer than the sync speed.
Short version, it depends on what you're trying to light. If you're trying to light water drips into a pan, all you need is a couple of hot shoe flashes. If you're trying to light the splash of a car driving off a dock, you're going to need more than anything I know how to use.
Don't know if that helps any; you may know all this already.