You can install QC12.2x with an architecture that will make it simple to add a node later.
DISCLAIMER: In order to do clustering, you must either have the ALM-Level license (not Enterprise), or the specific ''High Availability'' license from HP.
Clustering/multiple QC nodes REQUIRES that you have a network (not local) DB server, AND that you use a network location for your repository (not local).
The DB part you are likely already doing, but the Repository by default is on C: buried in the QC installation. During install of QC12, when you get the Configuration Wizard, one of the pages asks where the REPOSITORY is, here you specify a folder on the network (i.e. \yourNASserverfolderrepository).
Later, when you either acquire an ALM/Premier QC license or the specific ''High Availability'' license, you can install QC on a DIFFERENT server and when Configuration Wizard launches, specify Second or additional node and use ALL of the same credentials, passwords, passphrases etc that you used on the 1st node (good idea to take screen shots during first install).
When presented with the page regarding ''Site Administration Database Schema'' specify ''Connect to existing schema/second node''.
When the Wizard completes and deploys, make sure to apply the SAME patch as on the primary node.
Now, you effectively have multiple QC servers all serving from the SAME DB and Repository location. Each one can be addressed by it's corresponding QC address : http : // serverName:port / qcbin. Admins normally do not give out all of the URLs to end users.
Some companies now will put other tools in front of QC to provide an alias URL and switch back and forth between the various nodes as needed for fail-over or load reasons.