mehhh BTBAM tours enough, and they definitely draw more of the bullshit hardcore kid scene, atleast here in the states...
I really think that SA would fit well with Atheist and Cynic. I know those two are referred to with a bit more of a death metal aspect, whereas SA usually gets labeled straight prog (see Oyvind's post above), but I don't think the sounds are too far a stretch at all. Especially what with Cynic's new stuff. In the eyes of a fan it would be the perfect tour, and I'm sure that just about any fan of Atheist or Cynic would definitely dig SA.
Another cool idea would be Atheist, Cynic, then the new member's bands Gnostic and Exivious.