I think any of Jim's speakers as a center channel would improve the dialog, since they all excel in midrange reproduction. Dennis made a post just a couple of days ago regarding the differences between the Monster, and Monster Jr., if I can find it I will post a link, but the gist of it was that it would lose only a marginal amount of bass response. The mid-range should not be affected at all, so they should both have the same authority for voices. Correct me if I am wrong but I think the SongCenter would be the smallest of the three, and it would have the advantage of the exact same driver array as your ST/RTs, and it would also be the least expensive (I think).
Thanks for the compliment about my thumbnail... That is a picture I took while I was visiting an onsen (hot-spring) in Japan. The spring water had a very high iron content that caused it to look red. For obvious reasons it was called the "blood" onsen. As for growing my own Bonsai, it is something that I would very much like to explore. I don't have the outdoor space, or optimal sun exposure, right now to do it. I learned that the hard way (by killing a small "easy to maintain" bonsai due to lack of light). I will cultivate my own, someday. Are you into the hobby? I know it takes a lot of time, and patience to grow them properly, but it is a true art-form.