Totally agree with Christy Brock's answer, below. Again, assuming a short sale, all parties involved in this transaction - your stepbrothers and all agents - must sign disclosures that you have an "arms length" relationship. I would strongly encourage you to discuss this situation with your agent and your bank. Do not hold back on any details. No one, knowledgeable in short sale transactions, would allow you to proceed with this purchase without full disclosure of all motivations and relationships. There is too much at stake not to reveal all the facts.
Trans-Action Realty 500