You said you're using Black on switch vs CI... you could use Obedience instead, it has 40%CB and once it triggers Enchant, you'd have a 200%AR boost for over 10 minutes. The lack of IAS sucks, but you could use a fast base (or just charge with it until Enchant triggers, you said you had HS, so you have at least 1 pnt in charge)
But really, the best thing you can do for your CtH is to get more raw +AR... a few Steel GCs would probably help a lot, as would using the Raven Frost instead of Dwarf Star unless you REALLY need the fire sorb/MDR (getting a RF with a high AR roll would be good as well). A pdiamond or good +AR jewel in your helm would also help... and if you're not strapped for resists, you could replace the pdiamond in the HoZ with a good +AR jewel...
Alternately, a single point in Conviction (boosted by HoZ & Ammy) will do more for your CtH than fully maxxed BA (I know he's a frost Zealot, but just sayin...)
WoRG