Every week I get a slew of pamphlets through the door from home delivery services that offer pizzas and kebabs or pizzas and burgers. I pop them straight into the recycling bin and try not to look at them. The offerings make me feel queasy. Most of the places don't really have a website to speak of.
Here is one of the more successful examples of these homegrown pizza delivery services, they have a chain:
http://topspizza.co.uk/kentishtown/pizzas
Menu is pretty typical and I would say representative of the majority of take out pizzas consumed in the UK.

For those wanting a more "upmarket" experience (which seems to mean more goats cheese and blue cheese in the choices) there's this British chain:
http://www.organicapizzacompany.co.uk/our_menu.php