Those AllElectronics magnets look like a great deal! I bought a big bag of cabinet latches from the auction site for about the same price and had to cut the plastic body out of each one. Get some good gel CA or Goop and glue the sides on the magnet so they won't come apart. For a magnetic board, the first one I had was a bulletin board purchased from Walmart for $9. I found out after a couple weeks that the cardboard backing would warp severely, turning my building board into a huge white potato chip
. Get one of the better heavy duty bulletin boards from Staples or Office Depot, they'll stay flat and when not being used for building, hang it on the wall so you can post your RC to-do list.