You can get the LEDs that run off of the power supply easy. The fluro tubes are what require the brick. If you are just running for brighten/dim a fan controller (analog) can do the same thing (just a rheostat). What are you planning on using for the logo?
If you are planning on using plastic or glass there are some methods to home etch it that turn out pretty good (I use a small airbrush type tool with abrasive material after cutting the pattern from a sheet of masking material). There are also chemical type etching processes but I havent used those.
As far as color it depends on what your preference is. I prefer blue over red.
I have used waterproof LEDs in auto applications but I dont know if you mean submerged. So far I havent used anything submerged loose in a watter supply yet (led fountain lighting or inside of the liquid cooling system).