Use the motherboard's mSATA slot for one of them, and an mSATA ->SATA adapter for the second.
m.2 and mSATA are 2 different form factors.
My revised pick would be to get 2 of the Amazon linked adapters (keeps dust out better than the other items), and just not use the motherboard's m.2 slot.
Okay, so i can't use the slot on mobo..
What about one of these 2, much cheaper:
http://www.dx.com/p/hd2590-2-5-sata-to-mini-sata-sdd-adapter-enclosure-silver-289040#.VE1yNd45K0Q
http://www.dx.com/p/mini-msata-ssd-to-2-5-22-pin-sata-adapter-enclosure-blue-355877#.VE1yNt45K0Q
Those should also work as mSATA->SATA adapters. But you need to factor in availability and shipping cost to wherever you're located. Plus: there's the possibility that the mSATA drives that you're looking to re-use may be slow or of too little capacity to mess with. In that case, simply getting a new m.2 drive may be the better plan.