My cabinet is to low to put a skimmer in for the size tank I have. I was wandering if I can place the skimmer outside on the cabinet beside the tank and run lines to it. The inside height of the cabinet is 24in.
?? None of those are short enough to fit under your stand. Those are all external skimmers that you could run next to it.
If your tank was under 200g you could definitely find skimmers that are short enough, like 21" tall to go under your stand though.