Thats good thats it a timbre match. One issue I see with the STS though is that it has built in subs. The reason I see that as a con is that speaker placement and sub placement usually coincide. Also the specs on the built in subs are grossly overstated. According to third party measurements the -3 point is around 35hz. Even for music i think you'd want a bit lower. Dont get me wrong, I heard these once for a very brief time at an audio show and they seemed pretty good, very nice to listen to however I would still look at a quality sub with them. That does however reduce the need for towers and the built in subs for that matter. I hear its rather difficult to integrate these sub with a separate sub, I've never owned speakers with built-in sub so i wouldnt know.
I think you could get a similar sound to the sts with their bookshelf speakers. Like I said before there are a lot of great options to choose from. It all comes down to budget, auditioning ability, and WAF potentially.