i totally support what has been said positively about megasquirt, been great for my engines over the last three to four years.
however you do need to be prepared to learn a lot about engine management, if you get it wrong, it could be fatal.
so if you are prepared to learn and i mean lots of hours not a ten minute crash course then go for it DB37 connectors are fine, no need for anything more fancy, just don't expose to water and ensure screws hold it tight.