Scouting round this forum will give you all sorts of views on this subject with different ISP`s. Looking at the various reliability awards will give you a similar number of different ISP`s. Your best bet is to speak to others in your area and find out who they are with and how reliable the service is. At that distance from the exchange you shouldn`t have any problems with an ADSL (BT line) at up to 8 MBps - Virgin Cable has no such distance restrictions but there again the infrastructure in your area may be flaky so ask someone.
When you`ve made your decision get one of these people to recommend a friend (You) - they can earn a bonus from most companies and it`s worth a good night out in some cases! (£50 with Virgin I think)