Nurses and healthcare for sure. for 3 reasons i think.
1) there's just a lot of them. so statistically you'll find a lot of freaks who happen to work as CNA's, nurses, nurses aides.
2) they are stressed the fuck out and have a rather monotonous job...so what they need is from a partner is fairly straightforward.
3) they see all the wild and crazy and gross things the human body has to offer so they arent squeamish. if anything it opens them up to extremes of what human are capable of. I know one nurse who said her and her co-worker girls, when in the Ob/GYN or whatever it is where women go to give birth, would judge the expectant fathers and rip into them with jokes (behind their backs of course) if they thought they werent attractive or masculine enough to have impregnated the woman in the chair. In fact she did mention being around pregnant women and babies makes, and im quoting, a womans uterus throb. so there is that.