Few questions on having and engine built.

It's always a lose, lose, when someone that doesn't actually know what they need only what they want, wants you to build a engine for them. not knocking the OP that doesn't have time that is usually a different story. It will never run the way he thought and that's your fault and it cost more, that's your fault. Tell him what you want in a engine and listen to the engine builder, he will tell you what you need.