If you want Yamaha & is willing to pay, try U3 - the made in Japan model. A brand new piano is approx. $10k. The other model you can consider is U1 - made in Jap model, slightly cheaper at $8k+. These are the exam models used for the ABRSM exams.
However, pls note that these 2 models are good up to Grade 8 only. If you want an even better piano, then better to get a good European brand.