Custome Cake

Hi!

I posted this a very long time ago, but I'm hoping someone may be able to answer as I never got a response.

My FH and I are looking to have a custom wedding cake. To be exact, a tiered tri-color cookie cake. I have a sketch of what we are looking for but am willing to take suggestions from bakers if it is not do-able.

It would need to feed abt 170 guests

Please let me know :

a) when is a good time to start looking for bakers? is it to early now?

b) is this type of cake possible? do you have an aproximate cost?

Thanks so much for any information you can send my way!