just a general thing I like to point out that clams of noncommunagetic are hogwash and not recognized by the FDA in the US. They put them on to sound more impressive and Krylon if they are making that claim are only fallowing a trend.
That said I trust pretty much any and all reputable theatrical makeup brand over anything in the drug/depart,amet store in terms of cosmetics as they have no added filer or perfumes.
But as to body paint I recommend the liquid/water based ones as they will not rub off on other people you bump into, I stay clear of Homestuck cosplayers just in case because I don't want my costume stain grey (or Blood on other costumers >_<). You can then seal them with any setting spray to prolong their wear.
Mehron's line I've have not had an issue with patchiness.
Another option is to wear stocking on the arms and legs and paint for face with a matching shade of grey that you mix to match. That way you can have cream makeup on your face and not have to worry about your body.