Beware of the network maps that ISPS are so keen on. They only tell half the story. They do not give you any indication of the loading of the network by the customers. The other problem with the maps is that there is no standard so it is impossible to compare one provider to another. Meaningful service level guarantee.
Most service providers provide some service level guarantees.
The value of these varies from provider to provider. These are difficult to assess, particularly with service providers with multiple links. This covers the main points but there are other options you may want such as dual diverse bearer that gives a backup link in case the primary link goes down. This is useful if the Internet is business critical. Parkway Computer Consultants are willing to provide consultancy on both these issues.