Without knowing your work needs, how can any of us say?
The OF1400 is a marvelous plunge router and I did not see another router in your collection. Personally I prefer an OF2200 for jobs beyond the capacity of an OF1010, but that could be me. I bought an OF1400 when it came to the USA. It is a versatile router. Still, my suggestion would be to spend a little more money and buy the OF2200.
Because you ask about both the 106" (2700mm) rail and the Parallel Guide set, I assume you break down sheet goods. I also see you already own 2 55" (1400mm) rails. One approach would be to buy either another 55" rail or a 75" rail. This way you could leave the 2 55" rails connected, using the 75" rail to ensure the connected set was straight. For years before I have a large enough vehicle I did that, since it was not practical for me to transport a long rail.
Using the Parallel system, a single 55" rail is not efficient making 48" cuts, so for cross-cutting full 48" or 49" sheets the 75" rail would be a big help. With care and practice, plus Festool clamps, it is possible to make 96" cuts with a TS55 using a 106" rail. However, it is much easier using either the 118" (3000mm) rail or the coupled 55" totaling 110" Currently there is not a lot of price difference between the 106" and 118" rail.
Something else to consider for the future would be the purchase of an LR-32 drilled 55" rail for just slightly more than the price of an un-drilled 55" rail. With the LR-32 rail the appropriate LR-32 Guide Plate to attach a router and either an OF1010 or OF1400 you would be set to effectively drill adjustable shelf holes.