Going to motul.com and looking at your choices for non racing situations, you basically have one choice. What 6spd is using, the Motul Eco 5w30. The other two Motul 5w30 non racing oils are generally for diesel applications. That said. Do your research, a good place to start...
Motor Oil 101 - Bob is the Oil Guy - Bob is the Oil Guy
I went with
AMSOIL SAE 5W-30 Signature Series 100% Synthetic Motor Oil
But that's just me. I wanted a full synthetic. Interesting thing is that Amsoil does not say what their base stock is for their oils. All I have read is that it performs well.