What is the best size longboard/mini mal for surfing?

Go down to a local surfshop where they can custom make you a board. They will set you up with the perfect board based on your size and what you tell them you are wanting to do while riding. The possibilities are endless with custom made boards these days. I know a few shapers that have there own machines that are run off of a computer, you type in the dimensions you want and the machine pumps it out and the shaper does some finishing touches then glasses it. Besides, The professional shapers are going to know a lot more about what they are talking about then most of us answering your question (unless one of you answering is a shaper).