My team and I have an app which we\'re going to be submitting to the store pretty soon, but we know that we\'ll be selling the app to another company in the near future. Doe
As far as I know there is no way to transfer apps to a different user/company. I think the app should be in your customers account from the beginning. Otherwise you probably have payment problems too (people paying you instead of your customer).
Why not just sell the app to a customer before releasing it. If they want to see it running before it is released, just sent them a version built with an ad-hoc certificate.