looks like a good design, i would try to vent outside if possible. As far as a fan, you can buy an ac fan that just wires to a standard lamp cord but you have to look at how many cfm you need, and if noise is going to be a worry, there are many choices for a fan. Yield depends on so many factors that i cant offer you any advice. How many, what strain, training or topping, soil?
All in all it sounds good, good luck!:thumbsup: