Product designer - to design bath toy made from EVA foam

I am starting a business creating educational bath toys for children aged 3-7. The first toys are fairly simple: made with EVA foam to stick to the side of the bath. The shape of the pieces and what should be printed on them needs to be designed.
I need an experienced designer to take my rough sketches on paper and create professional designs - improving on what I have thought of, plus creating a specification and design in a format that can be used initially to make prototypes.
This design for this first toy is relatively simple; it will be 3 large foam pieces and about 20 small ones.
I need the design of the toy to be stylish and attractive so it looks great in urban bathrooms.
My company is new so these are not my products, but to get an idea of the kind of thing I mean, see these bath puzzles:https://quuttoys.com/bath-toys/