Joker11,
My shop installs a bunch of jet kit and of all the major brands. In most instances I prefer the Dynajet brand, as they tend to go a little further and seem to be a somewhat higher quality. Any of them will make a difference and will be money well spent. I also install Flo-Commanders, and find these to be a better choice if you can only afford one system. The Flo-Commanders routinely deliver greater improvement and are easier to install. Of course I recommend using both as they each have their advantages. On my ZX-11 the Flo-Commander delivered over 10 HP (at 6000 RPM, no less). I have yet to see a jet kit contribute that much, at any RPM.