Cypress mulch is a very good substrate but many people do not use it because it costs alot if you have a large collection. CEDAR on the other hand is the big no no for bedding as it is toxic.
Personally I do not use live prey, and if your BP is already eating thawed, it is much more intelligent to keep it that way. Live mice or rats can cause serious damage to a snake VERY quickly. For example if the snake were to strike and coil around the wrong end, the head of the mouse could bite and knaw at the snake enough to do damage before it would die. To any others that do use live, I am not telling you to change, this is just my opinion.
So I would just say, as funny as it sounds, serve your F/T "prey" on a platter for your snake, which could be anything from paper towel to a nice flat rock. If you are concerned about the snake moving once he has begun to eat, put his meal in a plastic container in the tank.