If you are planning what to do about TV after your move to Britain, you ought to be aware of the Freeview system, which makes all the major British channels, and quite a few minor ones (including HD channels) available via over-the-air digital broadcast, and is, as the name implies, free. However, it does require either a special set or a converter box. I think most or even all analog TV broadcasts have now ceased (within the past year) and been replaced by the Freeview system. You can also pay to get a number of extra channels over the Freeview system if you want, but there is quite a large free selection (not the hundreds of channels you can get on cable or satellite, but quite a few).
For that reason, you might want to leave your old TV behind, and buy a new Freeview enabled one one you get to Britain. If you don’t you are going to be buying a converter box anyway, even if your TV can display PAL.
There are also several competing paid cable and satellite services, but unless you must have several hundred channels, or your fix of American shows in first run, you might not feel it is worth the money. (There are plenty of US shows on regular British Freeview channels, but they will be run first after their US runs, usually at least a year after, I think.)
Also, all the major channels here now make a wide selection of their shows available online as streamed video. This is also free (there are probably some pay services too, but I have never felt the need to look into it). Personally, this is how I do most of my TV watching these days. I have my computer hooked up to my TV by HDMI cable, and watch the shows I want when I want to. (You will not however, be able to stream video from US TV company websites, or sites like HULU - not unless you indulge in a bit of illegal hacking, anyway. The US web sites will block you. Presumably other countries’ sites will too.)
Of course, when I say this stuff is free, that is with the understanding that to legally watch any sort of TV at all in Britain, you have to pay the TV license fee, currently £145.50 per household per year. This is the case even if you never watch over-the-air TV, and never watch the BBC (I imagine you could probably still watch the likes of You Tube on your computer, but not the streaming video from any of the UK TV services, and, as already noted, you wont be able to get through to any free US streaming TV services.) After paying that, though, there is a lot you can get for free.