why are you pulling in your mercedes in this thread? and your attitude is quite "strange"
firstly you ask for recommendation, then it comes that you have already bought the engine, when you said all you care is about speed, you get a suggestion and you answer that - it comes with ECU and transmission and you own a mercedes benz sedan. WTH?
did you read your post before hitting the reply button?
for starters - post the transmission model code that you have?