>I get to sell whatever we have created, code wise, and get the dough for it.

Many, if not all of whom you pitch your product for and are interested to buy it would ask you to work for them. Even if that doesn't happen, get prepared to handle lot of support calls; so factor that into the price.

>Anything I should do first, legally wise?

Invoice from your company that they are selling to you, for some token amount. Perhaps a legal binding agreement should help as well. Get advice from a proper legal counsel.