There is a method to it:
1. Try to describe the boat and it's program in a short sentence. For example, a power boat that a family of 4 would mostly use to go to the inlet beach on week-ends and occasionally for inshore fishing. Or, a sailboat for week-end cruises able to go to Catalina Island in moderate weather and accomodate 4 for up to a week. Try your own but keep it short.
That description will force you to make some choices because you can't have it all in one boat.
2. Set your budget realistically with a time table for expenditures.
3. Select a building material and method.
All those factors influence each other: if your budget is $ 10,000.00 over 3 years and you want a 31' inboard to run to the canyon, you have a problem. Solve that problem before arguing about the boat's layout on this board.

Once you have a clear program defined with the elements above, see if one of our boats fits the bill. If not, post a message with your program and we will respond.
We take realistic demands for a new design seriously
but we can not make the big investment that a new design requires unless we feel that the project is well thought and feasible.
About changes:
Some changes are simply impossible, technically impossible.
You can ask it as many times as you want but to put a big inboard diesel in a hull that is designed to be light will not work. Even if you squeeze the engine in there, the performance will be bad and we do not want to design that change.
Imagine that you want a Lamborghini but ask the factory to put a Caterpillar diesel in there. That's what is asked here sometimes and we can't do that, take our word for it please. But we can design a good boat with a diesel engine if you request something reasonable.
Put it another way and say:
" I want a boat with the accomodations of the DE25 but with a diesel engine , a top speed of 30 mph and a 200 NM range. My budget is $ 10,000.00 over 2 years."
We will respond: can do but budget must be $ 25,000.00 unless you reduce top speed to 12 mph or will install a used diesel.
And we can go from there.
Inboards will show up this year, several of them but we are listening to your request for more designs.