Watling Tyres at Sittingbourne is reasonably near. http://www.watling-tyres.co.uk/location/sittingbourne

If you're going to Brands then Sidcup Motorcycle Tyres http://www.sidcupmotorcycletyres.co.uk/ are just a few miles away. Lots of people swear by them.

It might be worth pre booking as most tyre places order their tyres for next day delivery if they don't have them in stock.

No association to either company.