Was going to suggest S60 but it seemed with the spec the OP had posted..

Jenvey TB's
Coil packs

he wouldn't need any functions approaching that of the S60. For basic fuel/spark, the S40 can do that all day. I agree that if you want to play with lambda, logging, traction etc then the S60 is the man for the job.

Again, OP needs to tell us what he wants to do with the ECU and car and whether he wants (or indeed NEEDS) to be exploring more advanced functions like those mentioned above.

TT