There is a reasonably functional set of house rules which include Karma-based character generation done up by
Serbitar. Links to his rules are in his signature.
Personally, I don't use them, opting instead to hand out Karma that are the equal of build-points. You get the same advantage of removing "breakpoints" where chaarcters can min/max themselves into being superior over the long haul and the math is admittedly a lot easier.
The imbalance of using Build Points and Karma Costs in the same game is pretty intense over long games, so doing one or the other seems like a no-brainer.
-Frank