Usually I go with a 50/40% split. 50% of the Karma, 40% of the money.
Those who play their characters well and smart and stay alive deserve to keep their edge in money and karma, after all they earned it.
Those who have died, sadly, have usually done something to get themselves killed (or, maybe it was blind bad luck...), get to make new characters, but Availability gets set to the highest availability gear owned by a surviving player. (So if the surviving players somehow got their hands on a Availability 24F item, that becomes the new limit to the new character).
I used to give full cash and Karma, but then I noticed that it was usually the same people dying the same way almost every single time.... And all they were doing was using the extra Karma and Money to essentially make the same character again, but better. So I cut it down to make them both use their heads and to see that the others were slowly pulling away from them so NOT playing like idiots.
(they got the message in short order. Now the deaths are more on the "blind bad luck" side of things and not on the "what happens when I walk in the police department and open up with an assault rifle?" side anymore.)