Ace is drilling my tank this afternoon and I need to pick up a set of bulkheads. It's for a 75 gallon tank. He said he thinks Aquarium Designs has them off 281/Brook Hollow. I'm either going with 1.25" or 1.5". Any idea how much these run? Are there different types of bulkheads besides the diameter? This is my first tank drill and I know nothing about them.