I'm interested on replacing the 12" fluorescent in the bathroom with LED too. That fluorescent creates a ton of radio noise.
Now, fluorescent bulbs require a high voltage, which is the source of the electrical noise. I'm assuming that voltage source is in the fluorescent fixture, not the tube. This means that replacing the tube alone will not remove the noise. Also, if you are replacing the fluorescent with the idea of conserving energy, you will want to replace the fixture as well. I'm sure a fixture that is designed for LED cannot be that much more than an LED tube itself.
Just found this neat site:
http://store.marinebeam.com/replaceable-fixtures/