Which register is this aircraft going on to?
First, arm yourself with the full requirements of a C of A for that aeroplane on the register you are going to attach it to.
Now, with the benefit of your engineer you need to to do a full C of A airworthiness test flight, are you up to that? Possibly you should think of engaging a well qualified pilot?
Don't leave Wichita until you are 100% happy you have a very serviceable aircraft.