Jeff,
The one important caution to be noted about using lipos as starter batteries is not to let them discharge too low. This will cause puffing and in extreme cases a runaway thermal meltdown. Many people use a small audible low voltage checker that plugs into the balance tabs. It beeps of the voltage drops below a safe level.
If you are not lipo savvy I would recommend this cheap piece of insurance. Look at Boris Mazor's starter thread.
TG