Alright mate
I know it's frustrating, where abouts in MK are you, as I know loads of people with Sky digital! The relay service is £2.77 per month, the top tier CATV pack is £38 for all sports and movies + £50 installation.
Unfortunately the cable is physically incable of anything more than this (ie digital), as it was laid back in about 1970, new bits of the network are still done by BT (ie the TV plates etc) but it's all run by NTL.
I'd double check about the status of having Sky dishes mate, as I have a few mates that live in MK all on Sky Dig, tattenhoe for example.
Let me know
I work in the Luton office btw
legend