BikespeedUK have always looked after me in the past, just give them a call and tell them what you have. The last chain I bought from them was an EK SRX2 gold with JT sprockets for £80.
Fitting a chain at home is a bit of a fine art if I'm honest, I usually cut the old chain with a set of bolt cutters to save breaking my cheap riveting tool, take a measurement with a digital caliper to find the width of the links then aim to press the soft link together at roughly the same width, following that its just a case of flaring out the tops of the pins from the soft link, too much pressure and they crack and too little could allow the plates to move over time.
If you're not confident with that process look around for places willing to supply and fit as fitting is often done at a discount for supplied parts.