I need someone to design a layout for my garden. It is a completely blank canvas.

Design details: I'm looking for someone to come up with landscaping designs for my garden so that my builders can complete this for me. My garden is approx. 11.7m x 18.9m.

I'm looking for a modern, clean garden; which will be built in 2 stages. First stage will be the main sections of the garden with the 2nd part to be building a "summer" house for the purposes of housing a gym.

Main features wanted in the garden is:
1. Section to grow own herbs/plants
2. Lawn area for kids to play
3. Area for seating furniture/BBQ
Ideas for the visual style: Modern, Zen, Easy to Maintain
Preferred colors: Grey
Extra notes: Wants:
- Grey paving/stones so that its an extension of the house. The garden is back onto from the living room which has a light grey flooring and in addition the kitchen which has a medium grey slate type tile flooring.
- Ideally, some sort of light features in the floor.