Considering that most of the versions sung today seem to have emanated from a single source - Peter O'Toole via Dominick Behan - I expect that "Kilkenny" will be consistent (and, methinks, consistently wrong). It would be great to come across a published version prior to 1960, so we wouldn't have to rely on one man's memory of what he might have heard.

Meanwhile, I'll put my money on "Kilmeny," which clearly makes sense, rather than "Kilkenny," which just as clearly does not. ;-)