I agree with the above post, you need an attorney to work on this arrangement with you and to build an agreement which will hold up in court. If at some point in the future things go south, you want your investment to be properly protected. I have witnessed many failed business ventures which started as good ideas but were not properly set up, and trust me things get very messy when it all hits the fan. If you have $50K to invest then you can afford to pay for proper legal advice. Good Luck!
I feel sorry for the person who can't get genuinely excited about his work. Not only will he never be satisfied, but he will never achieve anything worthwhile.
Walter Chrysler