TV is fine for movies and games but for general use, TVs make horrible monitors (trust me, I've tried it).
If all you're going to do is play games and watch movies then a TV will be fine, but if you want to do other stuff too, I recommend getting a proper computer monitor. 24" or 27" 1920x1080 or 1920x1200 would be my recommendation.
These are meant to be pretty good
http://www.newegg.com/Product/Product.aspx?Item=N82E16824236103R plug your PC in via DVI or DisplayPort and your PS4 in via HDMI and you should be good to go.