Have your wife set up an LLC and have her real estate contract pay her to the LLC. From the LLC, make her an employee and pay her a paycheck with taxes withheld so that you're paying SS instead of self employment tax. I believe you'll have to set the LLC to function as an S corp but then you should be able to expense many of the costs you'll incur and avoid self employment tax.
Your accountant should be able to set up the LLC for nearly nothing. I believe a Nevada or Wyoming LLC is the sort that would be the best for you, but that's something you'd need to clear with your lawyer and accountant.