The most reliable configuration you can achieve is to just leave the wing off and leave it in storage.

Seriously though, if this is a typical 40 size trainer, there's no reason to spend a lot of time and effort adding weight with extra batteries and regulators. Modern radios are reliable when properly installed (padded), and nearly all the choices for batteries are reliable. The dual battery setups, regulators, etc. are for the guys spending megabucks (read thousands) on large scale models where vibration may be significantly higher, and there's far more at risk.

If you install all the equipment properly, clip or tie connections together that you don't undo after a day of flying, follow good pre-flight procedures, there's no reason, other than pilot error, that your plane shouldn't last a very long time.

Brad