Yes, they will be. You'll need 60 EVs to achieve the same HP as a 31 HP IV Kyurem. I recommend you take them from SpA; the Speed was set to 216 EVs, accounting for the 30 Spe IVs.
I've found myself using Haban Berry more often. Most Dragon-types think they can revenge kill me, but thanks to bulk and Haban, I can KO them instead (or slow them down with Glaciate).