Trying to design a fault tolerant topology. I will be stacking all switches with the appropriate stacking cables, my main concern is if I can use the other SFP ports to create the redundant links between floors?
Cisco – creating redundant links using Cisco SG500 series switches
ciscoredundant-routesswitching
Best Answer
You are designing a network with 8 switches. In my opinion, it's a network big enough to invest a bit more in a core switch with more 10GB links. Make a pure star topology with a core (switch 3) connected to each switch trought an etherchannel/port-channel (2x10GBx7 switches = 14x10GB).
If you can't afford a core with 14x10GB, try to get a core with at least 7x10GB. Make a star topology with only one link per switch and get redudancy connecting each switch with another one (should be blocked by STP).
If you are stuck to this Cisco model, you can't do much better. Just try to connect switch 1 to switch 3 directly and switch 5 to switch 7. As a best practice, try to not chain switches.
As an opinion, at least, get a decent switch core ;).