Few questions on having and engine built.

I am in the planning process of putting together a stroker motor. I have never had a shop build an engine for me but for lack of time and space at the moment I am going to be taking it to a builder to have it done. I do not want to be overbearing and I want to make his job as easy as possible along the way. Should I simply take the motor to him and allow him to order all the parts? Should I tear the engine down to the block and just give him the block and heads and parts I will be reusing?

At the moment I am undecided on if I want him to just assemble the short block or the entire engine but I will using a shop that breaks in the cam and dials in the engine on dyno if they assemble the whole thing. I am hoping some of our professional builders chime in here with their advice.

If you are not far from Detriot, I know a guy there that can build it.