The bikeberry stage 1 is the TZ ignition and recommend it. I have the Screaming Roo variant (CDHPower). Found it started easyer to start, not 4-stroke randomly (boot) and high end does not vibrate anywhere near as bad as stock SD box.
The best thing I found about the Jag CDI is can be adjusted to enhance any engine mod you can throw at it. It also can improve your stock CG and smooth it out by changing the curve when needed thru out the RPM range. It's the best mod for your money. Mine is almost 1 yr old and has never given me a problem. I've used it on 2 different engines/GT5// PK80 both w/fredheads-OZmags-Dellorto 16-16s. PK80 is boost ported w/ OZ reed Both run great. I bought the version 6. He has some other versions @ different $. You can't beat it. (carry on)
It's bit more expensive but if doing a performance build with high rpm the pre 03 pw 80's cdi has a proper start advance with retarding curve as rpm climb and with the seperate coil produces good strong for higher comp firing and proper burn of more fuel.They can be found on ebay and online dealers and are used by Apollo Racing and others that do cylinder swaps aswell.