I'm looking into this table extension also. I like the idea of saving the shop space. It looks like you have the Professional with 36 rails and the Integrated Mobile Base. I have the 52" rail system, but otherwise the same. I talked with SawStop to make sure I was getting the correct router table and they made sure I had the exact model for my saw. When I called back, after much research and thinking, they said I couldn't get the router table. Their "Build & Price" functionality on their website said the same. The reason being, the Integrated Mobile Base isn't strong enough to support the weight of the Router Table.
It doesn't look like this is a big issue for you, as it appears your saw is stationary. I move mine everytime I use it, as I have a garage shop.
Have you moved yours much. Have you had any issues with the Integrated Mobile Base? I really like and want this upgrade, but don't want to hurt my gorgeous saw.