A quick review of the startup market here reveals a good number of nascent web startups seeking a technical founder CTO.
Kill Your Cube
Dating Site Startup
Recently a first time founder of a Boston startup came to us seeking a CTO for their web app. There was no great technical problem to solve, no dream team and no technical IP to create a barrier to entry. In short, nothing that would interest an experienced CTO. It was certainly a great opportunity for the right person, but that right person was a veteran developer with a track record of shipping reliable code. Mostly the issues were scalability, time to launch and usability.
Rather than waste effort convincing the type "A" founder that they didn't want a CTO, we focused on showing them lead developers that had shipped significant products and lead teams. Other sources provided many interviews with CTOs and experienced VPs of engineering, at a considerable waste of precious time, but none could be attracted to the deal. Eventually the start-up ended up hiring three good developers and had a very successful product launch.
If you are a non-technical founder with a Web App idea, just get something built. It is all about the Minimum Viable Product. Get something in user's hands, gather feedback and iterate until you have something they love and will pay for.
Build some traction and revenue, traction is good, revenue is king. If you take off, chances are you are probably going to throw out all your original code anyway. Once you have traction and revenue, you will be more attractive to the CTO you thought you wanted when you started out.