There are many ways to power a shock flyer depending on whether you want to fly indoors or out is one consideration.
For a 3 cell 340 lipo pack I would recommend a cdrom motor, like the LensRC 25t. I got mine at Model Airplane Engineering. Randy will answer your questions but he told me to use a GWS 9-5 HD prop with 3 cells, 10-6 with 2 cells. I get around 10 minutes hovering with this setup on my Superstar. It's a very good indoor setup and of course can be flown outdoors in calm weather.