GoPro's have a fixed focus, non-zoomable lens. Normally they shoot in 170o mode but you can change it to "narrow" (120o? - I believe) mode at some of the 1080P resolutions also. Your Sola's have a 60o beam width.
ULCS sells a double GoPro tray/handles to mount your arms. http://www.ulcs.com/gopro.html$135 with the two handles though, they're $50 ea. Reef sells it and they ship internationally. http://reefphoto.com...roducts_id=5579GoPro's have a unique mount.
The current GoPro 4 Black only shoots 30FPS in 4K if that's a consideration. It does however shoot 1080P as high as 120FPS. The Black is supposed to be the best in low-light also. If you want to see what you're shooting, you need to add the $80 BacpacLCD to it,
Or give up the 4K resolution and go with the Silver which includes one. I don't believe it's as good in low light though. But with your lights, probably not an issue.