The best advise I can give, and which I always see in terms of "which Salk is right for me," is to reach out to Jim and discuss with him.
I can't convey the minima of degrees of difference, here.
Frankly, unless you just want to spend the most money, I think the BeAT might be the way to go.
Hell, with Subs in the mix, you don't need the speakers to reach super low unless you like listening in Pure Direct. The 33Hz of the BeAT would win again. If you want a very pure experience in Pure Direct, then go for that 9.5" Satori Woof in the SS or Encore.
(You can see the minutia in this, I hope.
To be clear, just short of Pipe Organ, 25Hz is enough to clear the full keyboard of a piano, 33Hz will miss some of the lowest fundamentals there, but still be enough to cover Upright/Electric Bass.)
In terms of Centers and Surrounds, I've heard Jim may be working on some new gear to update and match his existing driver selections better.
Which again leads back to a conversation with Jim.
Beyond all that, keep in mind that the difference between the Encore and the 9.5 is not very much, for example. A different Mid, and some Passive Radiators. The BeAT uses a smaller version of the Satori Woofer. The sound quality here is not going to be significantly different, rather just degrees of subtlety.