Hi mdeuerlein,
it's been ages since I last posted here but I have a very similar set up to yours, and as it's taken me about 30 dives to figure out the settings that work best for me, I thought I'd share what I've learned so far.
If you go to this clip you'll see that you can get some quite nice colours pretty much straight out of the camera:
https://vimeo.com/74906163
Please read the info. on my Vimeo page. I have struggled a LOT with white balance compared with my old 3 chip camera. I've tried using a white slate, palm of the hand, then a slate with blue or grey pencil scribbled on it, with varying degrees of success and finally I remembered an old thread here about "expodiscs". It's a totally different method of white balancing, where you hold a piece of white translucent plastic right in front of the port , so it's touching (you'll need a red filter too, obviously), and then point it at the brightest part of the water, or white sand. You need to be in shutter priority with auto ISO for this step, because otherwise you will get Panasonic's "scene too bright/dark" error. Expodiscs apparently disintegrate underwater so, in desperation, I improvised with a bit of detergent bottle, cut down to the right size to cover the port, and attached on a lanyard. In the video above (apart from the hammerhead, which was basically a night dive!), the colours just "popped" really well. At the moment when I hit the WB button, sometimes I just thought "no way" is it going to white balance, but then took the plastic away and it was fine. We have a brand of laundry detergent here in Belgium called Omino Bianco, but I guess a lot of brands use white plastic bottles...
Anyway, here are the settings I use for the bulk of each dive:
custom hack - 50 Mbps, GOP 3 (I-P-P)
720p/50p, because it's better for slo mo and all my output is for DVD or web anyway so there seems no point in shooting 1080/24p
shutter priority, 50
either auto ISO (WHAAAAAT?!) or ISO 1600 if I'm under an overhang at 25-30m (like the glass fish in my video)
for macro, in future, I would use 1080/24p and the ETC function, so that I could crop for DVD if needed, but 50p really is cool.
At the safety stop of my first dive of a trip, I save the WB setting to one of the pre-sets so that I have something to use straight away for that moment at the beginning of the next dive when you see something incredible but don't have time to set up the camera. I also save one of the presets for white balance with my torch. If I'm doing up shots and want to get light rays etc. then obviously I'll switch to full manual and stop the aperture down.
I have the power zoom 14-42, which is plenty wide enough for my taste, and of course zooms smoothly.
Last word of advice. Practise with the controls on your 10 Bar. Frankly, they're really clunky, and I wouldn't be at all surprised if one of the control rods doesn't connect very well. It's the sort of annoying little problem you can sort out yourself by sticking something to the end of the gland, which I've had to do with the video button and the mode dial. No big deal, and I guess that's the reason why my set up cost 1000 euros less than the secondhand Nauticam housing my local dealer was offering me. Maybe take some super glue and puncture repair patches with you. However, there is one big advantage to 10 Bar: the two user-maintained o-rings on the rear plate are visible at all times, whereas I think there's only one on the Nauticam and you can't see it.
Have a great time in Galapagos!
Cheers,
Matt