always EVGA.. best warranty 
Warranty covers for mining usage as well? Or say you just dont mention it when claiming warranty? Most likely the later right ?
I would never mention mining in any warranty claims, to many reasons to deny you if they feel you overclocked or modified the card in any way to avoid replacing it for you. Provide as little details as possible and hope for the best, EVGA has had great reviews from customer service so they should not give you to much trouble if you need to go that route.