This is interesting to me. Feel free to send me some more details. Only one concern, can we keep our privacy? I mean there will be no disclosure of personal information from my side.
Why would you like a no disclosure agreement, this might put OP in risk since he will be sharing workload with you which means you will have access on the site and script along with payment for your work. Would be fair for you to give him assurance.
Grin nice venture. I hope the financial commitment (if it gets to that) is going to be well handled or escrowed since it is already in secrecy so that both parties won't come back to scam/accusation on such allegation. It is as advise.
This can be a good option to protect both parties interest and to avoid risk of getting scammed.
Good luck on your venture.