When you say LCR, that confuses me. I think of LCR as a passive soundbar (like the G-42 I have), but I know that’s not the case here. My fronts for music will be Klipsch RP-600m’s.
I think it would be helpful if you detailed out your whole proposed system configuration, and what stuff you already have. Because this seems unbalanced to me-$4500 just for a preamp, but then less on the amps, and nothing against the RP-600m however it is not matching the quality of the other stuff. Plus in such an expensive system I would want towers for better integration to the sub, unless you actually have those in a bookshelf. The G-42...I'm glad you have great intelligibility, but those little woofers and spread-out setup are not really how a center should run, especially in such a top system, it will limit you. Understand that the center channel carries a LOT of the sound information-not just for movies, but definitely for surround music
as well. Ideally the three front speakers would be identical, though many layouts mean exact match is not possible. In such case, to avoid "Venetian blind" beaming problems, you want a 3-way center channel: either with a midrange below the tweeter, or coaxial like KEF or ELAC.
When folks say LCR they mean Left/Center/Right, unless maybe you are in a soundbar-specific thread. So the confusion is your "C" has LCR (not very well for L/R since soundbars aren't wide so you don't get much separation) but it's just wired as Center.
If you want great stereo sound, your L/R speakers should be awesome. Speakers make by far the most difference to the sound by orders of magnitude. So this system sounds like a lot of good speakers with great electronics, rather than great speakers with great electronics. Some folks say "spend all the money on the upstream (sources, amps) because if they can't generate the signal well the speakers can't reproduce it" however they totally misunderstand how vastly more difference speakers make to the sound. And speakers do tend to sound better and better and better as you spend more money. Electronics, not as noticeably, and depending on your hearing maybe not at all.
Offhand, I'm suggesting you get an 11-channel RECEIVER, which can process power the whole stuff, and spend much more on speakers. Especially the LCR! The other speakers are important too but not nearly as much. This advice depends some on what you have already and what you are planning to get. If the receiver is not powerful enough for your listening levels, then you can add maybe a 3-channel amp for the L/C/R...and you probably need to add additional outlets on a separate electrical circuit, because you can only get maybe 1100-1200 watts continuously out of the wall.