we basically had what you have and went to sky+ a year ago, we pay about £32.00 a month, thats free calls weekdays/weekends (certain times) – unlimited broadband (which has never faltered and i play loads of online PS3) we have all the entertainment channels but no sports or film.
a mate had BT Vision and is p*ssed off with it, box keeps going nuts, BT are big on marketing but fall short of service in my book.
sky+ is bloody great, the only crap thing is when you are recording 2 programs you cant watch a 3rd which is the only point virgin beats it on IMO. but lets not get into that one 😉
if you push sky they will give you deals, there one on at the moment with a free HD box.