You should try to agree to a launch date and feature set.

He might be good on the business side but a natural procrastinator when it comes to project management, noone can have all the qualities or all the flaws.

If a feature set and deadline agreement is not possible, then you can always give him a dealine of some sort to reach an agreement: if in two weeks there isn't an agreement then the company isn't viable.

Because this is your company too, you shouldn't just find another job and move on. Give yourself a last chance to make it work, and if that doesn't work then move on but knowing that you gave it that last shot.

This way you wont look back and ask yourself what if.