Both Kyurem formes should have the same Pokedex number, which means you most likely can't use them on the same team.
Thank Arceus, stall has been spared a bit more :D. This did however bring up an intresting question in mind though, since both Kyurem's easily break down virtually all physical walls, wouldn't that let them pair up nicely with Rayquaza forming a wierd Double Dance strategy? Rather then using Rayquaza's Draco Meteor which fail to OHKO Specially Defensive Groudon geared to tackle that poke on, Kyurem White's Ice Beam will ALWAYS OHKO, and this allows Rayquaza to fully invest in attack, making it more easy for it to DD up and sweep (this does mean the removal of Scarfkia though).
I think Kyurem might encourage more hail, but what concerns me is the growing Stealth Rock weakness then. We all know Abomasnow's enormous weakness to hazards and sadly the Kyurem forms have the same problems (granted they can probably just whip out a Draco Meteor / Outrage at anything that wants to set up hazards and eliminate its presence from the earth but...). Also, with its Ice-typing and decent speed, anyone think it could become a decent late game cleaner with LO (this becomes even more viable with Flame Charge)? Rather then the problem it faces with Specs (which is switching in and having its HP take another 25% of its health), this attempts to actually stay in to eliminate the foolish Steel that tried to resist it moves via Focus Blast / Fusion Flare / Superpower.