I bought the Bartman spoiler, but have not installed it yet. I knew going in I would have to drill new holes, but think it will be worth it.
The spoiler looks amazing, I am very impressed with the quality of the entire kit and "bartman" was awesome, very helpful. I ordered it to match my Desert Dune finish and the match is spot on, really I cannot say enough about how good the spoiler looks. I will try to post a pic.
Whenever I drill into an exterior component I would use silicone to eliminate the chance of water getting in. I did not see if you mentioned using any or not, but I bet that would stop your water leak. Don't rely on plugs. When I install mine I will be putting a bead around all outer layer holes and another on the inside. He recommended this as well.
Good luck in your search, but I would go with the Bartman one. I waited a long time and was really worried about what it would look like, but man mine is awesome!