I have the standard Macbook (2015) - Along with the HDMI/USB Adaptors. I would like to get a solid external monitor for this laptop. I prefer Dell 23-26in monitors but am willing to look elsewhere. I would like to also have 1440p @ 60hz, preferably 1600p with a 16:10 ratio to match the mac standard - if possible. Is it possible to activate retina mode on external monitors? So if the monitor is 1600p I would like to sometimes activate retina 800p. Around or Under $400.00 - Thanks!