Wind has a healing spell, and so does Light once you unlock the fortune teller. There's also a physical ability that creates heal gems. Also, Earth is very good at moving gems, which can help generate larger groupings of heal gems if you really need to heal.
Water is generally pretty weak early, though I'm told it's powerful in later chapters (wouldn't know because I'm not a Patron).
The best defensive combination might actually be Earth/Wind, which gives you Rock enchant that can reduce enemy actions, Air enchant which can nullify enemy matches, physical resist gems from Earth, a heal from Wind, multiple ways to move gems (either specific gems or randomly) from both Earth and Wind, and Wind damage that will swap Rock gems with another gem randomly.