Basically anything listed in the 2015 thread or the 2016 thread will support 4K / HDCP 2.2 / HDMI 2.0a.
So last year's entry models would be S710W, S910W, X1100W, X2200W, and the new lineup is S720W, S920W, X1200W, X2200W....
Read through the first few posts of the 2015 and 2016 threads where JD and I summarize what's new, what's changed, etc. and you'll get a basic idea.
Note that for the 2016 entry-level models, very little has changed so at that price point IMO you should be targeting a good deal on a 2015 model.