This makes me smile. Not only because it's an interesting idea, but I tried the feat out as well with my Ogre Cleric of Zagyg. Good times.
The one thing to remember is that Touch of Golden Ice is an Exalted Feat from Book of Exalted Deeds. Getting them is different from regular feats, as is stated at the beginning of the Feats chapter. Need permission from the DM (of course), for they are handed down from agents of good (making them supernatural, not extraordinary). How you go about getting them is DM interpretation, but as it goes.
On the TGOI itself, the DC does not scale. It's exactly as it states in the Ravages and Afflictions section of the book. The DC could possibly be increased with other feats, but that's something you need to talk with your DM about. On that note: it was decided by my DM that I can't be wearing any Gloves of Dexterity, via the wording of "bare hand, fist, or natural weapon" on who contracts the Golden Ice. A ridiculous ruling when I look back on it, but I didn't know better at the time, so... *shrug*
Celestial Familiar and Exalted Companion are also in the book, allowing you choices of such creatures as
listed. These Companions are Magical Beasts, mind you, though the same traits that effect a regular companion still apply. How this all works together with Arcane Hierophant, I don't know.
In the end, do the research and verify with the DM. You got some interesting prospects here.
P.S. All Exalted Feats make you radiate an aura of goodness as well. Just thought I'd note.
