No Worries Ted.........and heh heh, I hope you meant 45F and up as your local coldwater, as 45C I'm not sure I'd even be in a swimsuit!
Yes GoPro sells small thin anti-fog strips, they're a must. Buy those they're cheap at $10-12 a pack, and you can re-use them 5-8 times each microwaving them ~20 seconds between dives.
Lighting, while not cheap, is for me anyways, is a buy it right buy it once purchase, instead of going cheap, then spend a little more, then actually getting what you really want the third time. Meanwhile two crappy lights gather dust in the garage.
To each his own, and you'll get lots of options/opinions out there in the web-world, but for a small and compact GoPro, it's hard to beat bang for the buck and size, of the SOLA lights.
I run twin SOLA 600 dive lights (the blue ring models) They're "last years model" no longer produced so you can find them on ebay or discounted at dive shops for $329 range. The next step up or present models are Sola 800 or 1200's. SOLA 1200's on sale go for about $579. Remember that Buy it Once Buy it Right motto of mine. I bought my twin 600's, for the price of a single 1200.
http://www.scubaboard.com/forums/gopro-video/439885-my-diy-hero-tray-travel-bag-light-arms.html
Some say "Filters only who needs lights" works fine, (which it is in open water) till you NEED fill in light or for shooting under a ledge or in a swim through.
For Filters, I'm very impressed with the SRP line of filters as they're very modular with Blue/Green water filters, and snap on/off even underwater. Others will say to run an in-camera gel filter which is cheaper and works too, but you're stuck with that gel filter even for filming before/after the dive while on the boat or surface, which basically negates any on-surface filming with an internal filter.
Go SRP, buy it once do it right. Backscatter also makes a nice swing-out filter, as well as other cheaper less proven options/mfr's.
SRP Home
PS, where are you staying while on Roatan? I've lived there before and worked at resorts..............yes it was a tough life..........Have some Flora-de-cana Rum for me..........grins