This may not be something you can control (so I'm making the suggestion to Xobni as well), but currently enabling Xobni extension makes Rapportive disappear. Before getting Xobni, I had my chats on the right-hand side (Labs) where Xobni now sits, then Rapportive would appear to the left of that. I thought it worked fine. The same would be true of Xobni & Rapportive working together, there's space for both, especially with chat moved back to the left.