My impression is like yours, people want the cats to look like boats and this might be the reason why the boxy cats we see are not selling so well, at least not in our waters where they otherwise would be ideal?
I have no interior made yet, waiting to settle on the exterior first. The hulls will be around 2 meters wide inside which allows for pretty nice cabins below.
The engines should be mounted as they are intended (see picture) on a V-bottom hull, but facing each other instead of pointing outwards. Must be even better!
On gas turbines, I love the sound! We had one of those skiboats running here last year and I was looking up for a helicopter...! Biggest obstacle on yachts is the cooling, which is often making the installation as big as a diesel with all the covers. Another is that they should not be sitting for months like yachts often do, turbines are better off where they are frequently used.
Looking forward to see your design in due time!
/Lars