my car is having the same problem as your on a cold start. idles like crap but at operating temperatures its fine. mine started to do it when i changed my injectors from 450 to 1050cc... i have a few guesses that might help you out, adjusting the tps screw on the throttle body and is your bov...
i was also looking for a cheap tuneable option, i ended up going with the dsmlink v3, expensive but very well worth it. i am new to tuning and it is a very user friendly program and there is lots of forums including the one on ecmlink with plenty of information. i would recommend going the the...