There is the option of having two separate Incra LS systems on the TS, one for the TS fence and one for the router. Then you don't tie up the TS when using the router. However, if you have the room, in the long run a separate router table would be the best way to go in my opinion from my personal experience. I like my set up with the the two LS systems on the TS and it works fine, but I were working with material on a regular basis that was over about 30" in length I'd have to make some changes. I could re-position the rails for thd LS set up to get up to about 40 inches of work space to the right of the TS blade but I seldom need that much space due to the work that I do.
It's one of those things that you have to take several issues into consideration, space, cost, personal preference etc. You have already got a lot of money into the TS. Let us know know what you finally decide to do.