Jason the SX1012 is an Ethernet switch. So Infiniband is not relevant here. To connect these switches between each other I suggest you use 2 cables type 40GbE DAC.
Cables are here LinkX™ - Mellanox Technologies
Then you can configure LAG/mLAG between switches for fail over. Start here MLAG Considerations for Mellanox VMS
To manage and configure switches you can use NEO which is free. Nice GUI and all. Mellanox NEO is now public!
Thanks for this Lior,
It was EXACTLY what I was looking for and those extra links are extremely valuable. Have a great rest of the day!