Custom Caravan Design and Plans

I need a design and plans for an old Viscount caravan which has been stripped back to a shell. I need plans that can be used by a cabinet maker, as he has requested them before commencing. I would like the caravan to include a kitchenette at the front of the van, a double bed at the back, and two single beds that convert to couches in the middle of the van with a small fold away table in between. We will also include an outdoor shower which is already plumbed at the back of the van. The layout style is open to suggestions. I know what style I like but have not finalised anything. I’m not sure what a normal job would look like, but I would probably like the job to first be designing a rough floor plan/layout for the van, then move to a more detailed design including measurements, electrical wiring, etc. if this is not the correct space for this work, please let me know.

Key Requirements:
- Design a travel caravan with a kitchenette.
- Include one double bed.
- Two single beds that convert to couches along the walls of the van. (May not be full size but just need to be big enough for small children)
- Include a table between the single beds that can either fold down or be removed and stowed.
- Incorporate an outdoor shower.

Ideal Skills and Experience:
- Experience in designing caravans and creating detailed plans for building.
- Ability to create an innovative and functional layout.