Thanks for the advice.
I had actually considered getting the DC2 card, but yeah, the 3-slot thing had kind of worried me. On the MIVE, they would be sandwiched together with no space in between them.
I also thought about going for the SC for the 5-year warranty that EVGA offers, but I tried looking up what the temps are like in SLI on the stock coolers for the card, and it seems really high (~80-90c in normal conditions). Thing is though, with the SC card, I could use the GPU duct thing that the HAF X has, in addition to the intake side fan, so I'm thinking that might help out quite a bit too. It's just a shame that the lightning card is too long to use the GPU duct fan on the HAF X as well, otherwise this choice would probably be a bit easier.