I believe these are the best low-self-discharge C and D batteries available these days;
D - http://www.amazon.co.uk/TENSAI-TR-C...=1423609600&sr=8-1&keywords=Tensai+D+TR-C8000
C - http://www.amazon.co.uk/TENSAI-C400...d=1423609694&sr=8-2&keywords=Tensai+C+battery
D - http://www.amazon.co.uk/TENSAI-TR-C...=1423609600&sr=8-1&keywords=Tensai+D+TR-C8000
C - http://www.amazon.co.uk/TENSAI-C400...d=1423609694&sr=8-2&keywords=Tensai+C+battery