I'm looking for gear recommendations to shoot environmental/lifestyle portraits for promotional/travel photography purposes on a 2 week trip to the wilderness. For most of the time I will be constrained to 12 feet and a fast moving subject with natural light because these photos will be taken on a small racing sailboat. If I'll be using my current camera body I would like to shoot at no lower than 1/(3*focal length) sec. shutter speed and no higher than ISO 400 on my current camera body towards the end of the the golden hour, or with overcast sky, so probably between f/2.8-f/4. I'm thinking of buying the sigma 24 f/1.8 prime (35 mm ff equivalent) for my nikon 300 body, and I'm also taking a 2 spare batteries for my camera, a small reflector and hot-shoe flash. Will this give me the versatility to do promotional photos, do I need a wider lens more/different gear? Is there some alternative technique/style that I might want to consider instead of buying or renting a new gear/leans and where can I read up on it?
additional info I don't have too much experience but my preferred field of view at which I'm comfortable with the distortion is 28mm-35mm full frame equivalent (around 65-75 degrees) but could probably work with a 24mm. I prefer deep field of view for most photos, but would like subtle bokeh when stopped down one f-stop for subject-background separation. I realise doing a test shoot on the boat beforhand would be the best option but this will not be possible before deciding on the gear.
my gear Off camera flash, reflector and tripod. Nikon d40 and Nikon d300, 18-200 f/3.5-5.6 lens, nikon aw1 11-27.5 f/3.5-5.6 lens. I could also probably rent a Canon mark II D5 body but would prefer not to.
purpose promotional/travel sailing photos for website taken on a 2 week sailing tour.
viewing conditions fullscreen website viewing on a 1920x1080 screen, possible viewing on a HD projector.
price range up to 850 USD, could invest around 350 USD more for new camera body or great lenses, but only if I really need it.
If there are any other factors I need to consider please let me know.