Dream -

there are three international size classes of multihulls most commonly built ...

1. a 1.2 meter MINI40/F-48 size,
2. a 2 Meter size and the
3. 1 Meter size ........... is quickly catching on.
Staying within one of these will result in a boat that can be raced, and will probably be sellable.

All are development class boats, and the F-48 has the least restrictive rules of the bunch. Speaking of this size, the class allows 1.2 meter (48 inches) length maximum, 1.2 meter width (48 inches) maximum, 2 or more hulls, and .93 sq. meters (1400 sq. inches) of sail area maximum. Working within the very unrestriced size rules, you are free to build what you think is fast. The MINI40 Class has a few contradictory rules, and the 1 Meter is similar to the F-48, except for size.

The 2 Meter class is obviously a bigger boat and the main difference in rules (and size) is the the 2 Meter class has a maximum mast height, and sail area is unlimited - just opposite of the MINI40/F-48 mast/sail concept.

I originally started with a NACRA 18 Square (see photo) as my base boat - 5.5 meters (18 feet) long, 3.35 meters (11 feet) wide and 18 sq. meters (194 sq. feet) of sail area - main only - no jib. This "real" boat gave me suggested scale sizes for my first r/c model. The hulls are approximately 0.076 meters wide hulls x 1.2 meters in length. (3 inches x 48 inches) You can start there, and most drum winches will fit inside the hulls. Arm winches won't.

I suggest corresponding with MULTIMAN as he has experience in production and sales if you are thinking of going that way.