If you're making a HaxKiss with the same purpose as HaxRachi I guess it would depend how bad the Ground/Fire vs. Electric/Ice/Rock weaknesses are for your team.Is Togekiss viable at all in OU? I've been thinking about using her for paralysis support/annoyance.
Jirachi's typing is obviously much better defensively, though Togekiss' 85/95/115 Defenses aren't bad by any means, especially with some investment. 120 base SpA is also pretty solid, even more so when you look at the insanely large offensive as well as support movepool Togekiss has.
Imo, Jirachi and Togekiss are two of the best parahax/support Pokemon in that style, so I guess it would just depend on what you need more for your team and how well you can compensate Togekiss' "lesser" typing.
Hope I could be helpful.