Seb,

Don't worry so much about the motor cut off on the ESC. Li Polys have a high internal resistance compared to Nicads, so there is a big difference in their terminal voltage under load and resting load. You'll notice for sure when the power drops off as the batteries get low, and that will be your signal to land. Just be sure the ESC voltage cut off won't be too high so it will be correct for the number of cells (2 cells, or 7.4V in your case, so a cutoff anywhere near 5V - 6V will be good). Some newer ESCs are now made for lithiums and correctly set their low voltage cutoffs at just under 3V per cell. This varies depending on who you talk to. Lipolys don't explode when discharged -- they explode when they are charged and the pack had previously been abused. If you monitor them whcn charging, you'll see them balloon well before they get dangerous. Of course, you'll need a charger specifically designed for lipolys.

As far as props, I'd stay away from the GWS orange props cause they flex a lot compared to the APC slow flyers.

Joe