From my perspective, the LS50 is a speaker that should be listened to before committing to it.
The imaging is probably better than any other speaker I have ever heard!
The detail is excellent as were most other aspects of these well designed speakers.
However, while I certainly recognize and understand why these are such popular speakers, there was something about their "presence/ambiance" that did not work for me. Since I heard them, I have been paying attention and seen only a small handful of others who, like me, were
not wooed by them. Statistically, you will probably love them, but it is a gamble. I'm sure you could find a pair to listen to your next time in the states if you make it a point to. If nothing else, a friend here could order through Crutchfield with a $15 return fee if you decide to send back.
But if I look at it as you have $1200 for L, C, & R; I would suggest you buy Canton Vento for R&L and the Canton Chrono center linked below. Right now this exceeds your budget at $1350, but I'd bet that come Black Friday, A4L will discount enough to make up the $150!
INHO, the ceramic tweeter used in the Vento series is too good for you not to spend another $150 and get it for all three speakers! Note that this particular Chrono center has the ceramic tweeter (as a trickle down into the top end of the latest generation of Chrono). Unfortunately, that is the only Chrono A4L currently sells that uses the Ceramic tweeter. I expect next year to see several Chrono models which use this Ceramic tweeter.
https://www.accessories4less.com/make-a-store/item/cantvento826.2blka/canton-vento-826.2-6-2-way-bookshelf-speaker-black-pair/1.html
https://www.accessories4less.com/make-a-store/item/cantchronosl556.2blka/canton-chrono-sl-556.2-6-3-way-channel-speaker-black/1.html