I have the same room and used the KEF LS50 Meta and KC62 sub to excellent results. I replaced the speakers with Magnepan LRS+. I needed some very powerful amps to run the LRS+ (unlike the LS50 Meta). I use a Sanders Magtech or a CODA #16 for the LRS+.
The LRS+ works great in this small room and it is better then the LS50 Meta. The soundstages is bigger, more depth and wider.
However, since the OP has a piano also in this room I cannot recommend the LRS+. I would go with the LS50 Meta
Actually, since the piano stays, you would be better off getting a RAAL SR1b earphone and the TL-1B interface box to use with your existing amp. It is better than the LRS+ and the LS50 Meta. However, it is not room speakers.