which turbo can help me picking up the .68 needed and just by changing the turbo will be enough??
First and foremost, you need data to tune with.
Data, data, data.
Get a Powerlogger, a wideband and a lightweight laptop to connect it to. Learn to read the data it provides. It's not very hard and there are plenty of people here and in the community that can/will help/teach you to understand it.
Without data, you're just throwing darts (or parts) at a moving target.