Hi, Roger....I purchased the Atkins Rotary Package, which consists of all your fuel and ignition items to install on a rotary engine. It included the MicroTech ECU with handheld programmer (actually mounted on instrument panel rather than handheld), 4 Bosch ignition coils, crank angle sensor, water temp sender, air temp sensor, spark plugs, ignition wires, intake manifold, TWM throttlebody with fuel rail and injectors already installed, intake manifold gasket, fuel pumps and fuel pump relay, fuel pressure regulator, and all the other little items I can't remember, which is everything you need to install on a rotary for fuel and ignition. It is basically a "bolt on" setup for the rotary challenged such as myself. Excellent instruction manual for the ECU with pre-wired harness (plugs into the ECU on one end of the wire, and the other end of the wires all have labels indicating where to attach them, such as red to ignition coil #1, blue to throttle position sensor, etc).  I purchased it because I felt it saved me time and effort by having everything selected and packaged up for me, so I didn't have to search for compatable coils, wires, plugs, injectors, etc.  Worked well for me because someone else did all the research and put together a package I could use.  Cost was something like $2900.00.

     Another good choice is the ECU that Tracy Crook sells. He also sells the engine monitor and PSRU (propeller speed reduction unit). Both Tracy and Dave Atkins have flying rotary aircraft and are knowlegable. I prefer to purchase from people that are actually flying what they sell.  If you go with Tracy's system, you will still have to build or buy an intake manifold, throttlebody, fuel rail, injectors, coils, plugs and wires, etc.   Don't know how the pricing would compare after you buy Tracy's setup and then buy the intake manifold, throttlebody, fuel rail, injectors, plugs, etc.  I believe with Tracy's setup you can use the stock Mazda coils, although I believe you need to install a resistor on the coils. With the Bosch coils, you do not need to install a resistor. 

      I found the MicroTech ECU very easy to install, and it has a nice monitor built into the hand held controller.  I have also seen Tracy's engine monitor, and it appears to be a very nice unit, giving you most everything you need to know about your engine on one screen.(On the MicroTech screen, you only see 2 or 3 items at a time and have to scroll up or down to see other screens).  The MicroTech ECU I believe has more things you can program into it, such as max rpm, max boost, injector open/close timing etc, and also has data logging.  On the other hand, there are more people flying Tracy's system, so there is a larger group of other builders to get assistance from.  I hope I am correct regarding Tracy's products. (Because I don't have them, I am not certain of their features). If I am incorrect, I'm sure someone will assist and correct me.

     I hope some of this info is helpful. Paul Conner, rotary powered SQ2000 in Mobile, AL