What is your budget for this camera? What is your priority for the hi-speed mode? While there are a few new cameras with optional hi-speed mode, I'd suggest that unless you are looking for true 400-1000 fps hispeed, you remove that from the list because it really limits your options. The things you can do with AE and twixtor / reel smart motion blur will cover the gap, as long as the camera does decent 60p at 1080.
If you really need decent hi-speed footage at those framerates, you are probably better off renting a solution than owning a camera with limited uses. That being said, the casio Excilim hi-speed series is really the only camera system in the prosumer price range that does good slow-mo. And even then you need tons of light and accepting cropped HD frames for 600 fps+.
The prosumer defacto "standard" right now is the Canon 5D mark III which will run you $2,500 - 4000 depending on lenses and options. I personally own a Nikon d5100 for personal still photography, but the video is quite excellent with a good prime. The autofocus is pretty good and you're looking at under $1k