As wwaswas said smudge from the forum runs mtbbatteries and in the past has sold NiCad batteries, currently there doesn’t seem to be any on his site, more people are wanting Li-Ion batteries these days. He may be able to fix your old battery if he has stock of some NiCad stuff still.
Drop him an email and see what he can do sales@mtbbatteries.co.uk
Otherwise he is selling a light with the most up to date XML LED in it, this has a slightly different design to the DX one and has been well recieved by others on the forum and is £67 – link below
http://www.mtbbatteries.co.uk/4.html
If this is still mre than you want to spend have a look on the forum for the numerous what lights threds that have been started in the last 2 months and there is plenty of people linking to Deal Exreme (DX) lights.