Check out the SJ4000. I have one its super durable, keeps a decent charge, and you can switch out the memory card. Its only $100, I love mine so far.

http://www.amazon.com/SJCAM-SJ4000-WIFI-Motorcycle-SmartTmall/dp/B00N8LHO1Q/ref=sr_1_2?s=electronics&ie=UTF8&qid=1421193126&sr=1-2&keywords=sj4000