If you want to be able to machine larger stuff and have the space to keep it then the XXL is the machine to go for, especially if you’re primarily working on wood or plastics.
There are some differences between the SO3, XL and XXL in terms of achievable performance but this is primarily about the speed at which you can machine, not the final results. There’s more detail here;
You can do quite big things on the XXL, especially if you ‘tile’ the work by sliding it through front to back and maching part at a time, I’ve done pretty large and complex bits of birch ply for furniture this way.
Dust extraction is important so good choice on the sweepy boot. T Tracks are a matter of personal taste, there’s many threads on wasteboard layout, threaded inserts vs. T Tracks etc. but you’ll figure out what works for your work.
I like the bitzero but since putting a full VFD spindle on mine I use an edge finder almost as much as the bitzero. The newer bitzero V2 works on more corners, products are constantly improving.
What are you planning to put at the other end of the dust hose? A dust deputy style cyclone settler upstream of your shop vac is a good plan, if you don’t alread have a full on workshop dust extractor system.