Sure. Just manually bracket the exposures by actually taking more than one picture of the same scene instead of managing it all with white balance in post processing of RAW images.
As for JPEGs of course. The HDR merge works just fine with 8 bit files too, just the same arguement applies to tonemapping a HDR generated from 8 bit files as 16bit files. Depending on how heavily you edit it you may end up with posterisation (sudden jumps in colours instead of smooth gradients).