What contract do I use???

I have a California Real Estate Brokers license, but I am just starting my own real estate investment company. I am involved with three other people, one of them is my wife. If I use a web site like Realty Trac.com to find a property that has a notice of default, and is listed on the MLS, and the owner is living in the house, WHAT CONTRACT DO WE USE??? Can we use a regular purchase agreement, or the new Notice of Default agreement. Is anyone familiar with this NOD purchase agreement? If so if you could send an example of this contract it would be great. I am anxious to get my first deal, but dont want to blow it right away by writing a bad contract.

Please help.

David
ndrealestateinvestments@hotmail.com