There are 240 Hz TV's, but were made for Active 3D to reduce flicker and crosstalk caused by 120 Hz TV's, when compared to 120 Hz Passive 3D. The difference when watching movies, or any content other than 3D, is not noticeable between 240 Hz and 120 Hz. Right now, the highest they go is 120 Hz, though last years model of the Samsung H7150 is using a native 240 Hz panel, but have seen none this year. Typically when you see 240 Hz today on the market, it's referring to interpolation, and so the native refresh rate would be 120 Hz. A quick way to find out, would be to check the spec sheet to see if the TV supports 3D, if it does, you know it's native 120 Hz, be it Active or Passive.
LG TV's use IPS panels, they aren't even comparable to VA in dimly lit or dark environments, VA is clearly superior for entertainment such as movies and games. Some IPS TV's are using local dimming, or what LG calls micro dimming, which is not the same thing, though they do achieve a higher contrast ratio than they would without it.
Right now, 4k content doesn't exist. Any movie enthusiast would stay far away from streaming 4k, because not only is it demanding when it comes to your internet connection, it's also comparable to our current blu-ray discs, which is not a good thing. Blu-ray comes ahead, despite the tiny difference in video quality, when it comes to audio. Blu-ray is king, and 4k blu-ray will completely take over streaming once consumers can watch local demos of how big the difference is actually going to be. Though the only downside to this new yet unreleased standard, is that it's likely going to be expensive, discs, players, receiver, and so on. A good thing however, is that current blu-rays are likely going to drop in price.
To answer above. 1080p to 4k upscaling doesn't make it match the 4k resolution, it's filling the pixels, but doesn't work like that. The signal coming in, cannot come out sharper, the TV's can't add information that's not there in the first place. What it's doing is trying to replicate what it would look like viewing 1080p on a native 1080p TV, on a 4k TV, that's all.