Only you can decide what is best for your situation. After reading about the backup options in this book, put together some sample backup plans; run through a few likely scenarios and assess the effectiveness of your choice.
In addition to all the other information you have learned about backup strategies, here are a couple good rules of thumb to remember when making your choice:
If the backup strategy and policy is too complicated (and this holds true for most security issues), it will eventually be disregarded and fall into disuse.
The best scheme is often a combination of strategies; use what works.