I'm kinda leaning towards the Asus because of the wall mount would be great but I can easily live without it
this monitor has almost no input lag, so playing your games should be no issue. you'll need to get a seperate audio thing, such as a small soundbar or jury rig something together. highly rated on amazon as a monitor
and this one doubles as a tv, has built in speakers, and generally great reviews
U can use a tv. I prefer a 70 inch that I have makes gaming fun.
Bigger is usually better but not for some games. For FPS's, I do way better on a 23-27" up close than on a 55"+. Less eye movement and better reactions using your peripheral vision. Those 70" HDTV's are great for movies and sports though.