Best Amplifier & Speakers combo?

Sound quality wise, CX81 and LS50 were better rated.  However, with LS50 priced at $1600, I will add a few hundreds and go with Buchardt S400 mk ii for its more extended frequency range (79hz-28khz -> 33hz-44khz ±3 dB).  LS50 is renowned for its midrange but S400 mk ii is not far away.  S400's extended, airy top end coupled with much more weighty and articulated low end enable you to enjoy music more.  You do not need sub for S400 either.

I would offer two suggestions.  1-Take the LS50 over the Q series, noticeable bump up in SQ IMO.  Both of my kids bought used LS50s and are very pleased. 2-The non-Meta KEF R3s are being discounted now and should be a strong consideration.  They will sound a bit fuller than the much smaller LS50s since they have a dedicated bass driver.  I'm sure they will do better with a bit more power which can be an upgrade down the line.  Good luck and cheers.  

I vote for the LS50 as well, but I am biased because I have them. However, I recommend you broaden your amplifier search to find a bit more power. Even at lower volumes the LS50’s benefit from an amplifier with some depth. 

The LS50 Meta is a great speaker. In my room, it was much better than the LS50. Even in a small room, the KEF KC62 sub makes the LS50 Meta a homerun. Without the sub the bottom end is lacking.

The better the amplification on the LS50 Meta the better the sound. I tried the LS50 Meta with the CODA #16, Benchmark AHB2, PeachTree GAN1 (modded), and a few others. The more power the better and the quality of amp will also show through.

I recently got the Magnepan LRS+ for my office and I "think" it is better long term than the LS50 Meta. I use the LRS+ also with the KEF KC62 but it is not as essential with the LRS+. I have my LS50 Meta for sale now since I am lacking space to put it, but I may change my mind and alternate with the LRS+.

My room is 12 x 11 x 9 with 4 extra feet where I took out the closet door and stuffed my desk and computer monitors. This seems like the ideal sized room for the LS50 Meta and LRS+.

BTW - I am getting a PeachTree GAN400 amp ($2K) coming today for my LRS+. I have a feeling it would be great with the LS50 Meta and work with the LRS+. Maybe not as good as the modded Peachtree GAN1 I have but the GAN1 would not work for you.