I am not a computer geek, but as far as I can see the main limiting factor in getting any speed with broadband, is your telephone line and the distance to the exchange. The old GPO copper cables were great in the 60's and 70's but not really up to speed for what they are now being asked to do. Many proividers offer high speeds but if they use the same telephone line, you are no better off.
The only option is therefore to get a fibre optic cable system to your home either through a new cable, or satellite. For the former, you also need the cables present in the street system, which is the case for most urban areas. I have been considering it through the Virgin offerings but I would need to be assured that the cable installation was neat and unobtrusive, as there is nothing worse than cable running across blank walls. Companies always assure you they have your best interest at heart, and then Joe Hammer their trained navvy comes along and just bangs it in anywhere. As the market is getting more competitve all the time I am inclined to wait a bit and see how cheap it gets.