Trying to setup my TV as a monitor - best TV size to get?

I know little to nothing about this, i currently have a 26 inch lcd tv 720p and its only enjoyable if i scoot my comp chair about 3 foot from the tv. So black friday is rolling around and theres a killer deal on a 46 inch lcd 1080p. Would a 46 inch be too big to enjoy most games? Are there any problems or issues i should watch out for when choosing a TV as a monitor? (like bigger the tv, bigger the strain on the graphics card etc.?) just theorycrafting and assuming since i have no idea what to do.

Best kind of TV to use for monitor are the ones that support 4:4:4 color production, or else the text would become blurry particularly red and green color.

My 42 inch LG seems to work great..I only drag my PC out to it when im playing a game that I prefer to play on my 360 controller..I use a mini HDMI/HDMI hookup..Works great.