I have been looking at lots of different sensors and prefab cams but all the numbers bewilder me. Can anyone point me in the right direction? What I am looking for is a sensor that can record at least 500fps in something close to HD( 1024X512 would probably do.) It would record to RAM 2,4 or 8 gig I guess and then dump out to harddrive. Basicly like the Photron FASTCAM 1024, but cheaper. Is it possible?

Many thanks, Ludvig