Maybe just a few points to the previous text I wrote. It seems you have some incorrect ideas about ECU stuff.
Wide band oxygen sensor
is NOT something related to emission control and catalytic converters you threw out of your car. Please get that.
It is a very precise measuring sensor and needs a controller to work and a display. Sometimes controller and display are integrated into one part.
The controller is used by the ECU AND by the tuner to adjust fueling. If, one day, your tune is perfect, you can eliminate the wide band. Anyway, at that point you will have realized, how useful this instrument is and leave it with the ECU for limited auto adjustment and frequent checks.
To make this perfectly clear: Without a wide band sensor there is NO aftermarket ECU tuning! Impossible. So get one. It is no maybe later, but the first thing to get. If about 150$ for it are too much, keep your car stock.
Get it before you need it, put it into your daily driver and become familiar with what it shows and what a working engine uses while running under different load conditions. Better than installing it to an engine with basic tune and wander what might be right or wrong.
Theoretically, you do not need a display, as TunerStudio, the mighty software (another 100$), displays it at the screen. In practice, you should have an independent gauge to verify what TS shows. All beginners make the same mistakes by taking short cuts at ECU wires and ground points. At least one exact working gauge helps a lot to sort that out.
If you want a good, reliable, wide band that is worth it's money, go to 14point7. Alan offers his the Spartan2 Lambda controller, which is very compact, reliable and needs no calibration. Buy the sensor there, too, as he sells real (non fake) Bosch ones. His display is an easy match to the Spartan2. His service is first class, not the usual ignorance known of other brands.
Other products will work, too, even be much more fancy and confusing. Look Innovate, AEM, Zeitronics, PLX or google "wide band lambda display". Some dealers put fake, Chinese Bosch LSU sensors into the set's to make more profit. Even in combination with real controllers and displays. These usually give all kind of problems or fail very soon. If you buy directly at the manufacturer, 15$ more can be very cheap...
Trigger
Get familiar with what they do. It is not your job to decide what gives the ECU signals. It is the ECU. You will need a crank wheel with about 30-60 teeth. The distributor signal will not work well. On the other hand, it can give the additional cam signal, which is very useful for advanced fueling strategies. So crank first, distributor (running at half crank speed) maybe later. It does not determine "when to fire". It is the most essential information for the whole ECU.
Wasted spark
Such a coil has PAIRS of high voltage outputs. The spark energy travels from output 1 to spark plug 1, then to engine ground, back through spark plug 2 and finally to the coils output 2. No distributor. Obsolete.
The two Spark plugs are at cylinders which reach UDC at the same time. In a 4 stroke engine, one of these fires the new charge, while the other is filled with exhaust gas at the same time. So both plugs spark at the same time. As a spark travels very easy in a hot gas, most of the energy is left on the plug with the fresh, cold mixture.
Such coils are available as 2, 4 and 6 cylinder versions ( 3 and 5 cylinder do not work!). You can get passive coils and modules that include the drivers. Speeduino is best used with build in drivers. Cheap.
Please, get good information
There is a lot of information about injection and ignition on the web. Use the Speeduino wiki. The MegaSquirt has a lot of information too. If you are shy reading, I would go there:
http://extraefi.co.uk/support/downloads.html
You find documents "basic fuel injection" and ignition there. Read it. Very compact with colorful pictures. It does not get more easy!