My trigger wheel is the Ford CV Joint Trigger wheel at 120mm dia with 12 equally spaced teeth. That is a circufrence of 377mm. 377/24= 15.7mm tooth spacing. It works fine with the BMW sensor.http://trigger-wheels.com/store/contents/en-uk/d24.html
If you don't want sequential injection, you can use a 36-1 trigger with either the stock distributor or wasted spark. As you will probably have to make a new loom, you may as well go for sequential with individual coils as it is not much more work. I'm using Denso coils off a Honda VFR800 motorcycle with a 30mm extender fitted to make them long enough. No issues so far.
I am running MAP correction on my set up, but the map signal is pretty noisy at low engine speeds/wide throttle openings. I'm not convinced of the value of this at this time and my try it without, just correcting for baro.
Like a wrote, the S38b38 cam sensor is the easiest and chapest to use.
You will need a TPS. I use the BME E46 M3 sensor with a spacer from here...http://www.massivebrakes.com/accessories.php?p=S14_TPSadapter
It is neat and tidy.
Air temp sensor mounted in the intake would work fine. There are a few intake options from the carbon DTM replica I have or the "Rongineer" boxhttp://www.rongineer.com/m3airboxkit.html
Which looks stock.
I am also driving my temp water gauge, oil temp gauge and oil light from the spare ouputs on the ECU. I have a cal file I can share and probably drawings for the crank trigger set up also. drop me a PM if you need them.