I believe DMDicks used to use a Haltech with his 2.0, if you email him you might be able to get a base map from him.
I would go standalone if I were you. You're already going to be tuning with the piggyback you're using, just with a very unpredictable and uncontrollable variable: the OEM ECU. I'm in a different camp if you can tune the OEM ECU, buy I don't really like piggybacks in general.
There are also plenty of cheaper standalone options you could use, one I've always wanted to try is speeduino.