Towel Warmer Above Tub

I am trying to figure out the best place for a wall mounted towel warmer in my bathroom for our remodel. I would like to place the towel warmer at the foot or head of the tub, but the place where it is going does not allow for much space between the wall and the rim of the tub. I know that you can't have an outlet "directly over a bathtub" but I'm not sure how much space is needed between the outer rim of the tub and the wall with the outlet on it. If there is a couple inches of decking between the rim of the tub and the wall is this ok? If not, would a hard wired towel warmer be ok at this location?

I am assuming I don't need a didicated circuit for the towel warmer, I can just tie it to the GFCI outlets in the bathroom correct? I think these pull less than an amp as the ones I've been looking at are in the 80 watt range.

Thanks,

Richard