I once helped a guy set up a home theater on which he spent about $15,000 on very good speakers and electronics, but his beloved antique cabinet would only house a 42" widescreen TV. What a crime. I think letting a cabinet dictate your choices is a frustrating (and avoidable) situation given how many cabinet types/sizes there are out there, and unfortunately your 7" height restriction is going to rule out a lot of great center speakers and significantly reduce your remaining choices -- at least for a good center speaker (even a third LS50 is too tall). Too bad, especially since you're rightly very concerned about dialogue clarity. It's a great pet peeve of mine too and why personally I wouldn't compromise on the quality of a center speaker. Hopefully you'll get some workable recommendations from the good folks here.
That said, I do agree with Dbphd that if your front L/R speakers are capable of producing clear mids and image well and your listening position is close to midway between the two speakers you might be very happy (and maybe even happier) without a center speaker. I had such a setup for several years and didn't miss a center channel one bit. Personally I'd rather have dialogue reproduced by two high-quality speakers than one compromised speaker if that ends up being the choice, but like I said maybe you'll get some good recommendations that will preclude that from being the case. Again, best of luck.
That said, I do agree with Dbphd that if your front L/R speakers are capable of producing clear mids and image well and your listening position is close to midway between the two speakers you might be very happy (and maybe even happier) without a center speaker. I had such a setup for several years and didn't miss a center channel one bit. Personally I'd rather have dialogue reproduced by two high-quality speakers than one compromised speaker if that ends up being the choice, but like I said maybe you'll get some good recommendations that will preclude that from being the case. Again, best of luck.
