During Trustee Sales you must have cash in a form of a money order or cashier's check. There are no other forms of payment allowed. If you're interested in a property that is going to sale/auction then find out the sale date/time, go to the court house and see if anyone bids on the property of interest. If no one does it will revert back to the bank and come on to the market in 30 days or so as a REO (Real Estate Owned)/bank owned property. Either trustee sale or REO you can get great deals in today's market.
Best of luck!