I'd rather have a slower lens with 4 stops of IS than a fast lens. Also, if photographing food is important, even in premium cabin the food is going to be really close to you. You'll want to see what the minimum focus distance of your lens is. And remember that if you get a fast lens, if you're taking a photo at F1.2 or 1.8, etc, your depth of field will be really shallow. And if you decide to use it a smaller aperture to get greater DOF, you won't have IS to help with the increased exposure time. And aircraft generally are not smooth platforms, its something you'll really notice trying to take a picture inside an aircraft cabin. The IS makes a huge difference.
You'll also often find that airplane windows vary in optical quality. It often doesn't matter at all how good your gear is. And forget about taking photos out of a RJ window, I'm pretty sure they scrub those things with Brillo
I've also found that windows near the boarding door are often in worse shape, I'd guess due to the jetbridge shroud rubbing on the window exterior.
I've never had any issue taking photos with my DSLR in the aircraft cabin, the noise is minimal compared to the ambient noise while in flight.
Anyway, I love my window seats and haven't yet gotten tired taking photos out the window
I'll usually figure out the optimal seating based upon where I'm expecting the sun to be and what we might be flying near. Enjoy!