Does Scott have a camera now ? If so, is there an underwater housing already available for it ? If your not sure, I can find out with the make and model.
If Scott is looking to get a new camera for this trip then it depends on how much you would want to spend. Would Scott really want to spend out on a housing, which can be expensive, for what could be potentially a few dives ? It might be worth asking Pro Divers if they hire out cameras, which many operators do. I am just thinking of the cost implications, weighing up the cost versus the amount of time and use you will get out of it.
As an instructor, I do not let any of my students, or recently qualified open water divers bring cameras when they under my tuition. I find they get engrossed in taking pictures, then forget about the basics of diving, failing to look at their air consumption, concentrating on bouyancy etc as minds are else where taking pictures. This was happening all the time to me, (it was giving me grey hair) so I have stopped this which is a personal decision. It's easy to get caught up in the excitement of a reef and get carried away taking photo's, next thing I knew I had people with no air to breathe......trust me, nightmare...lol!
If Scott still wants to get a Camera and a housing, I can only advise on what I personally use, and that is Canon. I use a Canon S95, brilliant little camera for above and below the water, the Canon housing is relatively cheap as housings go, but the housing are really well made and pretty sturdy, waterproof to 40m but I have taken mine down to almost 50m, and it didn't leak. My photo's are on 7 days somewhere, or you can view pictures I have taken with this model on
www.warrenssite.com and click the Maldives tab and you will see a gallery from March of this year.
A mask can make or break a dive, if you get a mask that is a poor fit and leaks, then it will be a pain in the ass and Scott will find he will spend the majority of the dive clearing water from his mask every few minutes. It's great that Pro Dive offer prescription masks to loan, that's pretty cool, is it free of charge ?. You might find by the time you have rented one, it's half the cost of purchasing one yourself, which you will have the added benefit of knowing it will be a good fit and wont leak. A mask you would use time and time again, I am sure Scott would be snorkeling at some stage, and if looked after, it will last for years.
Your local dive store will be able to provide lenses, and Scott can ensure it fits OK etc prior to purchase, (the mask should stay on Scotts face without the strap being around the back of the head, this will indicate that it is sealed correctly to the contour of the face. If it falls off, then air is getting in to the mask, which means water will also get in when diving). There is lots of good mask manufacturers to choose from, I have used Atomic masks for the last 3 years which I can vouch for as oustanding, I have also used Mares, Scubapro in the past and they are also pretty good, there will be lots to choose from. It's the fitting that is important at the end of the day.
This is just my own view, there is no point on spending hundreds of $ on dive gear if your unlikely to use it frequently, and you can rent it out there. I would say a mask is one of the few things I would take of my own, it's like being expected to run a marathon in trainers (sneakers ?) that are two sizes too big for you if you get a mask that dosent fit right.