Yep, the GH2 is wonderful. I shot the ON3P Factory tour edit on it:
If you're looking for a camera just for vid you CAN'T beat it... especially for this incredible trip and traveling in general. it's light as shit. If you're looking for a camera that will shoot incredible photos as well i would suggest sticking with Canon - although I haven't seen what the GH3 can do yet, it might be better than the GH2. I do not like using the GH2 for photo at all.
As for the UWA - if you go FF get the Tokina 16-28 f2.8. It's a great lens.
How are you planning on stabilizing your footy? that's a big consideration too. Tripod?
Also - where are you going? I can give some feed back on traveling with cameras depending on where you're headed.