To clarify, all you need for users to be able to do is register on the frontend? What are they registering for? What kind of data are you managing in the backend, just the user-submitted info? Do users need to be able to log in after registering, and if so to access what? I would most likely build the site on ProcessWire, an open-source PHP content management framework. Being that I am not a designer, I can at least recognize what looks good and bad, so I can select pre-made templates for us to choose from or emulate. You can see a few measly examples of my past work at http://grinddaily.net. I have more in development on my localhost with more impressive features if you'd like more info on those. I'm very interested in working on custom projects such as this so I do hope to hear from you, and good luck.