Any tank will work just fine. I don't recommend using two tanks for it, though.
You REALLY shouldn't be relying on dodges/parries to get through Decimation blade, though. If your healers can't keep you up through a deci without a dodge, they're doing it wrong.
A DK tank is the most optimal for this fight, but again, it really doesn't matter.
Is this 10 or 25man and what healers are you using?
Just saw on wowprogress you're 10man, but what healers are you using?
Edit: Looking at your log it seems like your healers don't understand the fight tbh, your best try at 4:34 your paladins were on 55 and 66 stacks.
This is how it should go:
Shard 1: Spriest solo soak - Both paladins spam heal to gain stacks.
Shard 2: (If you go feral dps, you can solo soak this one) Have paladin 1 solo heal shard, paladin 2 helps shaman heal tank.
Shard 3: Paladin 1 solo heal again, by the end of this shard he should have 150-200 stacks, allowing him to easily keep the tank alive on his own for the rest of the fight.
Shard 4: Paladin 2 and Shaman healing shards from now on.
If paladin 1 gets tormented, have paladin 2 help with tank healing and the shaman can solo heal shards while paladin 2 is busy.
The key on heroic is getting 1 healer high stacks early so they can deal with tank healing. First shard both paladins should be on at least 60-70 which is how many your healers are getting over 4:34 atm. Also, solo tank it, it's much easier for healers to focus on one tank if they do the stacks right.