Re: 26' Hurricane - 260 or 2700
I do not have a spot light installed in mine, I use a portable one when needed as I don't normally go at night much. It's usually that I may be coming in a bit late and I get caught in the nighttime and not much to worry about that a portable light can't handle. With a good GPS and 20/20 I usually do pretty well without even turning it on. As far as location of installation if I ever was to install one, (which I have thought of) that is definately the place where I would install it (on starboard in front of helm) in that little flat corner in front of windshield. Although I think your concerns are legit as far as some reflection or obstruction with the bow I think the overall brightness of the light beam will dominate your line of sight and you wouldn't notice if there are any reflections. The reason I believe it is the best place for it is because that is one of the areas of the boat where there isn't much going on, it is directly in front of the captain who is the only that really needs to see and your only other options could be in places where someone could easily bump it and damage it when out having fun at the sandbar and so forth.

IMO, the only real concern there would be passegers being in the way of the light beam and that would be the ONE time where you would have to tell everyone to stay the HELL out of those seats, LOL.
As far as gas, please don't worry. I have been pleasantly surprised with the gas comsumption on my 115's, even thought I think they work hard to move that boat while getting underway thus my mentioning in my earlieer post about repowering. Obviously there are many factors on comsumption, # of passengers, throttle, water conditions, wind etc. but overall I am very pleased. One small piece of advice is to gas up on every trip that way you won't feel the HUGE pinch of filling a 100+ gallon tank all at once. That would hurt. I have been up to 5 outings of variable speed, distance, and load usage without gassing up. Did this only once to test and see.
Overall your second option looks like the better one, even though you would be losing 40HP and getting Hondas instead of Yammies, which I would prefer, but 60 hrs vs 300 and some of the other things seem like a clear advantage. With the 130's you should be able to hit 40MPH without a problem.
Sandbar, one more note, and I think it is the most important thing that I have come to learn and appreciate in my 5 years of ownership. Any extra $$ you stand to invest in gas, maintenance engine x 2, you will more than gain back with the confidence you will have of knowing that you will never be stuck because one motor fails. You will be confident initially and after your first incident (inevitable) you will be very thankful for that 2nd engine. There is no feeling of confidence greater than that one.
I can't ever imagine having only one engine now.
Keep em' coming, I love talking about my Hurricane.