Mine don't hum... And they are pretty instant on. There is maybe a 5 second delay while the ballast spools up the voltage. If you're uninsulated and unheated, that will make a difference, but even at 35-40 degrees, mine come in pretty quick.I like the price of those a lot. I hadn't come across these in my search, thanks for the link! We're not to far off from the same footprint, your photo looks like it provides plenty of light. 6 of these (2 on either end, 4 in the middle should provide what I am after).
I thought florescent for a bit, as they are cheap. The humming sound wouldnt bother me one bit, but I do like the "instant on" that LEDs provide.
If I were installing lights today though, I would probably be getting LED.