Playing around with the layouts of my scamp before I start to rebuild.  Purchased fridge and 15gallon water tank with superflo pump.  Could use any suggestions/comments.  Recognize there will be mistakes along the way, but with guidance from this site hopefully I can avoid a few.  

Just today putting in wood support to right of door.  Putting in wood screws would not go in.  My guess is structure to attach to is metal and needs self tapping screws?  Wood support to the left side entry screws go into wood easily.  Any knowledge on this one?

Thanks