There is some British stuff on Usenet (e.g. nzbGeek) but yeah in general I have concluded that British TV doesn't have broad appeal and so it is hard to find even if willing to purchase.
You could also try using a VPN with the BBC iPlayer app. I've done this before.
There is also the acorn TV app which is a paid streaming service, $8 a month, and probably the best option if you're really into regularly watching British TV as there isn't really a great alternative option.