How can we get a "Web Designer & Software Programmer" as a profit sharing business partner..?

You need to have your potential partner understand your idea and like it. It is another validation for your idea. If it is good, someone will be happy to become your partner. If no-one is interested, you might need to reconsider it.

In any case you surely want a well-experienced designer / developer as a partner. Such guys and gals earn much :) In other words, if they are really good (and thus can earn from other customers) they can afford spending some of their time for your project.

Alternatively you can always hire someone less expensive, but hiring has nothing to do with partnership.