Hope some of this helps.
First question. Do you have a decent quality Internet connection?
1. Speed above 6-8Mb needed for responsive downloads at 1080p HD picture quality. (you can record out of hours as well) 3-4Mb for standard resolution if you are not worried. This should avoid stammers in viewing if you hit download _and_ watch in real time. If you want 4K/UHD then >16Mb/sec would be a guide.
2. I would recommend an uncapped data allowance if you start to pull TV through the Internet to avoid extra bills. Most companies provide this now so look for uncapped or unlimited tariffs. In general the providers user portal shows you how much you have used.
There are a lot of ways of getting TV through the Internet.
1. Netflix or other online services.
2. Amazon Prime (combines well with delivery if you Internet shop a lot)
3. All4/BBC iPlayer and other channels that are free over the web (I expect they will go to subscription in the future as little is honestly free)
4. Sky also offer NOW.TV which is run from an iThing or PC and allows you groups of channels over the Internet. It is mostly the same model as Netflix with a login and access to bundles of content through your PC.
5. It is rumoured that you can share a Sky account.....ahem..... If someone has Sky they can add additional logins to their account and the other person can use the iPad or PC/Mac tools to watch pretty much everything through this. So if someone has Sky and does not mind sharing (it costs them nothing) you use this with their bundles if you can link your iThing/PC to the TV. If for example someone wanted Sky F1 like my SIL does.
Most of these sites can run from a laptop etc. Slave an old PC or laptop with an HDMI connector into your TV and get a bluetooth keyboard to use from the sofa is one clunky option. You have to use an HDMI as this carries the content protection needed
You can buy one or more of the small plug-in boxes but these are generally single-tasking and only give a few of the channels. There is a good review of them here.
http://uk.pcmag.com/media-hubs-receivers...evices-of-2018. Many of these are to allow older TV's to use them and newer smart TV's have these built in as menu choices (applications).
Modern SmartTV's have software on them to play many of these channels (iPlayer/All4/Netflix/Amazon etc) from the TV itself so avoiding other boxes. In this case beware that they usually have a single tuner and so what is being recorded is also being watched in general. Some more expensive models offer dual tuners (one recording to USB/Disc and the other being watched) but these are less common.
Most of the modern TV's have the ability to put a high capacity USB memory dongle in the rear which also acts as the disc to store/record programs for later review. Some older models may have capacity limits on these so beware if you do want to carry a lot when away on holiday for example. Example
https://www.amazon.co.uk/SanDisk-Ultra-USB-Flash-Drive/dp/B00YFI1A66/ref=sr_1_4? In some cases you can also add a small external USB disc drive instead of a USB memory fob if you do need greater capacity. USB discs can be from 1-4Tb. Some take power through USB and others have external power of their own. - example
https://www.amazon.co.uk/ADATA-Stylish-External-Drives-AHV620-2TU3-CWH/dp/B00JK9NESW/ref=sr_1_17? These need a little more power from the USB port so check if this is suitable before going ahead. Happy to guide if it helps.
A Sky+ box normally has a 1Tb disc as a guide as it was designed for normal and 1920x1080/FHD. The new SkyQ box has 2Tb as it will need to store 4K/UHD/40962160 which has up to three/four times the storage per program/hour. If you want to go nerd-like and calculate it there are tools here
https://www.videohelp.com/software/sections/bitrate-calculators Any of these spring good/bad you want drilled into ?
