I wouldn't worry too much about the HDMI problem. an HDMI switch is pretty cheap, especially at mono price (I got a 4 port one with a remote for like $25 years ago)

I was also looking at the Vizio M series, but ended up going with a samsung F6300 for a bit more. One of the few problem I read is the vizio's screen is pretty reflective, I've also read it can have some problems with fast motion, but I've never personally viewed this TV so I can't say if thats actually a concern.

Looking at Amazon, I see this Samsung F6300 for just under $1300. Whcih is the smaller version of the TV I just ordered myself. This is a better TV then the Vizio from everything I've read.

Also, I wouldn't be too hung up on 240hz... in most cases (at least at your budget) its really a 120hz panel with motion processing to make it 240hz. I personally turn all motion processing off on my TV's as I can't stand the "Soap Opera Effect" it causes.

I'm a fan of the Vizio M series, but there is one thing you need to know. Default settings on any TV are garbage. The Vizio especially seems to have issues with new out of the box TVs having settings for the lowest common denominator. Here is a list of things to check for when getting a new TV.

• Set it to a "Home" mode rather than "Store" or "Display" mode. This allows you to make your own settings and have them stick.
• Change your TV display mode from "Dynamic" or "Standard" to "Cinema" or "Movie". This corrects the color and adjusts the picture to a more accurate and better quality image.
• Turn off frame interpolation (unless you're into that) which is default set to on on most TVs and makes everything have the "soap opera effect".
• Disable Overscan. Overscan zooms in on the image and cuts off the important details, why this is still default set to on baffles me, but things like news tickers, sports scoreboards, and movie subtitles can all be cut off by this feature. You often need to disable it for each input.

As for models to look at, if you are into gaming you should look at Sony which has very low lag times on many of their TVs but cost a little more. Samsung has some quality TVs for the price like the non-3D $1300 F6300. Avoid LG, their color accuracy is bunk. If you need more HDMI inputs, you may consider an AV receiver (/r/hometheater for more info and advice on upgrading to killer surround sound) or an HDMI switch.