Add a primary or a secondary?

Question

The current site has one primary and one DP for about 5K clients, everything is working fine. The client wants to add another Primary SCCM server to serve a remote site with roughly 1200 desktops and lower bandwidth, and the same time allow app deployment, patching and imaging for both sites clients to continue if the current primary fails.

Am I better off adding a secondary or is another primary a better option? I made the client aware of the Administration overhead, my primary concern is fail over for the core task on the current primary, the client is not interested in a Passive stand by since it will not solve the remote site issue.