Design an open plan kitchen/ diner/lounge

We are a residential property company based in London ( www.kctlondon.co.uk ).
We’d like to know the approximate costs for you to design an open plan lounge/kitchen incorporating a kitchen with island that’s attached to a small dining table, furniture layout and media area. The room is approximately 5700 mm long by 3800 wide.
I will provide my pwn written ideas, photos of existing room and floor dimensions.
You’re welcome to browse our website so as to get a feel for what we are trying to achieve.

Thanks in advance and look forward to hearing from you.