Hi, I personally would not use megasquirt and the like but do you intend to map it yourself? I see so many people selling cars or posting on forums "needs more mapping" as people never get it right.
You will see time and again on here...pick a mapper and use the ECU they recommend.
I think Dave Walker at Emerald is not that far from you.
I would whole heartedly recommend Mark Shead but he doesn't use the cheap stuff.
You may also do well picking up a used Vipec or something like that on here.