Hi, I can currently get a 1080 for 500usd brand new. Which I am planning on building a 7 gpu rig with them. what OS/miner should i use? I was initialy planning on using simplemining but for maximum profitability I should be mining Skein which isn't in there. So what should i mine?

P.S. I was thinking initially of getting 7 1070 but for 70usd and you get a 1080 which will have a higher resale value... So i am not really sure which path i should walk.