Hearthpwn

Valeera the Hollow

Or 

Arcane Giant

The rest of the deck I am pretty comfy with, but I have one slot and I don't know what to put in there.  The giant is really nice and I have run two in previous decks which can really add some pressure. But Valeera has also saved my butt before, and creates some great synergy with Auctioneer late.  

I just always feel like Val is such a late card and often dead.  

I believe that both should be in the deck, but Arcane Giant gives so much value especially if you can get an early Gadgetzan Auctioneer turn. Valeera the Hollow is so late game that it essentially doesn't matter up to a point. If you can win before turn 9, you don't need the hero card.

Val.

also, I would choose Fal'dorei Striders over giants as they add a lot more board presence over time and synergies well with miracles game plan.

Leeroy Jenkins is also a key card since miracle lacks the burst without him imo.

I have seen a few variations, just trying to find what seems to play well lately currently I have 1 Giant and I am sitting Val out.

Sorry should have linked my deck:

Honestly I wouldn't use either in this meta. A mid range miracle rogue would do best