Please explain the difference between the CurrentUSA T5HO fixture you're using and the E-Shine LED fixture your using. How are they different other than the fact they are different types of lighting. Both are fixtures, both "plug and play", and both have the exact same mounting concerns (unless your solely speaking about mounting onto the SM100, but even then a small ABS template to wrap around the LED light would solve that issue). Even CFLs have mounting concerns to worry about as well as humidity/corrosion at the socket.
You mean waterproof like the CurrentUSA T5HO lights that are recommended for the SM100? There is a product called LED Seal, just spray that on and you water proof the LEDs.
http://www.ledsupply.com/9013-07.php
http://www.youtube.com/watch?v=07yWAi5Wkdo
Maybe in your neck of the woods that describes the majority of aquarium owners, but that is completely opposite from the aquarium owners I know and I have worked at a LFS and talked to thousands of aquarium owners, out of that I can count on 1 hand the number of people not willing to do anything DIY for their tank. Certainly opposite of just about ever member on this site. Even if that were true and the majority of people wanted "plug and play" and nothing to do with building, anyone can Google "LED Grow Light", you will find hundreds of types and styles, some are even water proof. With all the different types available on the market there is one that will fit in any scenario imaginable, and worst case you have to spray some LED seal on it to make it water proof, which you would have to do on any type of lighting in a humid environment if your truly concerned about avoiding corrosion.