I agree with Dennis, a Nexus would likely be the logical road map. It has much deeper resource pools, i.e. buffers, CPU, and memory, that are needed server level of traffic burstiness and such. Add to that, these are much more rugged switches, built for higher reliability. A 2960-X is made for low-level enterprise and SMB user access, with the reliability and resources needed to feed that much lower SLA demand. That being said, the use case, SLA requirements, and future plans need to define the recommendation. If nothing beyond layer-2 between your firewalls and ISP, to a single 10GE provider link, I would say a Nexus 3600 would give you the reliability a performance you expect with lots of growth ability over the next 5+ years. Don't forget, when talking data center, extreme buffer depth and IO performance are must haves. I would expect to see significant buffer related drops in a 10GE delivery DC if trying to put a 2960, 3650, or 3850 series user grade switch into these roles that their hardware resources were not designed for.
