Just don't use the really cheap low quality coax (copper clad aluminum instead of pure copper core and poor shielding ) especially on longer runs. The original cable that Virgin use is hardly the best quality it's RG6 spec made for them by Antiference, so any half decent cable with a proper copper core and good shielding should be fine you don't need to go over the top and spend silly money on the most expensive cable even more so for short runs where it wont make much difference, poor coax cable issues are more prevalent with longer runs.
