If the cable to his house is capable of running 2 modems at 10mbit and theres enough space on the equipment for him to have 2 connections then i can't see any reason why he can't have a 2nd connection
After all NTL are a company If the customer turns around and says HEY i want to buy more from you and they have the capacity to provide it would seem a bit silly to turn ya away!
If your prepared to pay for it can't see why they wouldnt sell you it
