[welcome]
I would get the TS75 and MFT/3 package, clamping elements and quick clamps or TS75 and CT package. You can save a little buy buying a package. If you already have a work bench and/or shop vac you could could use what you have and get a TS75 package with either the MFT/3 or CT, and save for future purchases.
Or, If you could save a little more and get the TS75, MFT/3, CT and clamps, that would be ideal (this is what I did.) Trust me, once you start buying Festools you will not want to stop.
Without a table saw you will want the extra cutting capacity of the TS75 to build furniture. The only negative with the track saws is cutting small pieces, and as you said you can make dados with a router.
Another thing to consider is guide rails. The TS75 comes with a 75" (1900mm) rail and the MFT/3 has a 42" (1080) rail. If you're cutting down sheet goods you will need a longer rail like the 118" (3000mm) rail or you can connect two rails together with 2 rail connectors.
Sorry for the long reply, but there are a lot of things to consider that may not be obvious.
Enjoy,
Daniel