Buy this suction mount, NOT the official one. Far superior, and this is the one the pros use when filming.
You WILL need the bigger battery, even with it mine doesn't last more than a few hours if you're on/off/WiFi. That is, unless you run it from USB all the time which I now do when in the car if at all possible.
Any monopod will do, just find a cheap one from eBay. You can use the GoPro thread adaptor you get with the suction mount I linked to to attach it.