E-Trade et al will settle in cash for stocks

I had heard Jim Sinclair and Bix Weir say that E-Trade, Scott Trade, First Trade will settle in cash when TSHTF because they actually don't buy the stock any more than SLV or GLD buy the metals. I have a Roth IRA with First Trade but I would like to go to someone dependable who has the metal. I was told by Sprott I needed at least 50K before they would take me. Any recomendations?