At the risk of inflaming an issue (not my intent ) that really comes down to a difference of opinion, a couple comments:
Megasquirt, is OK but it is not for everyone, just like a Camaro is OK but it is not for everyone, How available is it overseas? If it is available, how much more would it cost, and how long to get replacement parts? Come to think of it, if someone in the USA was driving through Montana or Wyoming (or anyplace between the 2 coasts) and their MS unit died, what would they do? Sit down and build a new MS-II or shell out another $500 for a prebuilt model, then sit around waiting for it to arrive?
Would a method similar to what I have in mind be better? Maybe not, but maybe. The processing unit is a jelly-bean, off-the-shelf item available at Radio Shack, Fry's Electronics (or its non-West-Coast counterparts) and Amazon.com... plus hundreds if not thousands of locations around the world. Anybody is free to make them, so they are ubiquitous and inexpensive. They are small enough and cheap enough that you can keep a spare in your glove-box or your shirt pocket. It should be possible to design a no-frills sensor and actuator board that could provide basic but acceptable driveability and that would cost $20-ish, and that could also be carried in the glove-box or your shirt pocket..
It is also, by its nature, extensible. To whatever anyone wants to try.
On a more personal note, nobody, not even my wife, knows what I enjoy and why. I have already enjoyed this journey more than I could express.