I don't think you get a choice in that matter since its determined by nature or some other thing

Hidden Power is determined by a Pokemon's IVs, I believe.
Additionally, it took a power drop to 60. Hidden Power isn't really all that necessary a move to run.

But if Altaria were to run a Hidden Power, I think Fighting (Taking out those pesky Rocks and Ice who score super effective hits and Steels that completely resist Altaria's STABs) or Steel (Hits Rocks and Ice just as hard as Fighting, with the added bonus of hitting Fairies, but losing Steel coverage).

We'll it looks like a day to play Pokemon it's -50 c out here where I live. Which is -56.6 f to you guys.

Soon i will begin my hunt for a shiny Furfrou.

Battle? c:

Trying to breed eggs for the right nature for Endorf, since I couldn't find the right one >_<. What sucks is I'll need to get his evolution item...

Magmortar?

Anyway, I've recently begun work on a Dusclops/noir.

Nope :p

I'm trying to decide what to train next.

Weren't you hunting for a black Furfrou?