Is there any alternative to Cisco's VSS or vPC? I mean not with other vendors, just Cisco? Because I'm planning a new network design here in our company and I'm not really sure, if there's an alternative to the two.
First of all there is a big difference between VSS and VPC where Nexus vPC is introduced with Nexus 2,5 and 7K. The vPC is actually eliminate the need of STP on the member vPC ports and allow for efficient load sharing capabilities .The VSS on the other hand is a feature introduced with Cisco 6500 catalyst, its basically combines the Back plane throughput of the two systems which allows for high forwarding rate between ports, it also simplifies the management by making two physical switch operate as one logical Switch(like stack wise in 2960,3750 series). enter link description here
Second there is a difference between VSS and other redundancy protocoles like HSRP and VRRP , where VSS operate so far like Stack wise in 2960 and 3750 series single IP will manage all the chassis but in HSRP and VRRP you had to assign each chassis one IP and then gave them the Virtual IP but one drawback that VSS can't be supported in all chassis
Finally if you just want to obtain redundancy between chassis for fail over purposes you can run VSS,HSRP,VRRP for cisco IOS and VPC for Nexus. if you aim to also obtain single management IP you need to run VSS only but it is depend on the chassis