The "hybrid" solution is really only applicable up to hull speed. Putting in more electrical generator and power is pretty much a waste. If you're putting in a gen set and using that to drive at low speed you only want enough power to push you at hull speed up wind. Beyond that the electrical genset and motors are just adding weight. I don't have any idea as to how much power that is for the size of boat you're working on, but if you put more electrical power into the boat you're wasting weight and spending money on something that has little value. Since it doesn't take much power to push you at hull speed, (upwind) then the hybrid stuff can be a lot smaller and lighter.
Gas turbines in the 1,000 hp class aren't going to be very efficient. Light and powerful, yes, but efficient, not really. If you look at the specific fuel consumption of gas turbines, small helicopter engines typically have a takeoff SFC of about .55 lbs of fuel per horsepower hour, SFC gets better for turbines at higher percentages of power, so you don't want to loaf along on turbines. But at the same time, the helicopter duty cycle is different than a marine duty cycle. In a helo you take off and land at high power for a fairly short period of time, but then you load along at 50% power or thereabouts when you are in level flight. For this reason you really can't operate a helicopter engine at takeoff rated power in a marine application at high a power without shortening the life and if you back off the SFC gets even worse. In order to get reasonable overall performance (that is, not suck fuel like crazy) you need an SFC of about .45 lbs/hp-hr. If you get down to that neck of the woods, the weight you save by getting rid of diesels will reduce the displacement enough that if you want to cruise in the 30-40 mph range the turbine will be in an efficient power band . If you look at the available engines, helicopter engines in general aren't very good since their mission length is short they don't need to be very efficient. The T700 and RTM322 are good (too expensive and too much power for your application) and so it the T800, (a bit too big and really expensive), where the PT6 is less expensive but is also very thirsty, as are the Walter and the Turbomeca engines. You may have a turbine picked out, but I don't see how you're going to get competitive with diesels in this size class vessel. If you were going bigger (say the 65 to 80 foot class) then there are several solutions that make sense, but smaller than that you're going to have 25-50% higher fuel burn than a conventional diesel setup and that's fine if you have money to burn (literally), but most folks would get tired of paying the fuel bills for that kind of boat.
As to maintenance, turbines are much lower maintenance than a diesel, most maintenance is "on condition", if it doesn't break don't worry about it. Oil changes are in the 1000's of hours period or not at all. In a marine application a good practice is to spray fresh water into the inlet for a minute just before shutdown, but that's pretty much it. When you look at what it takes to keep a diesel in terms of regular maintenance, turbines require very little attention in comparison.
