Compu-Tronix looks like it makes a lot of sense, no air gaps, plugs fire directly from coil, with "distributor" working as a pure triggering device.
The DIS4 is supplied with a billet aluminum triggering rotor which converts your stock 009 distributor into a triggering device for our electronics package molded into the new lid. By designing a system that does not use a cap and rotor, we have essentially worked the bugs out of your Bug… and helped you into the 21st century!
If you fit it to an 034 distributor or, the modern 009 equivalent SVDA, then it's hard to see how you could improve on it without going the really big bucks racing route. (although this one's not dirt cheap either)
I wonder if it comes in 6 volt?
Regards,
Matt.