My 97 Disco had leaky oil cooler hoses and I just replaced them. I purchased them from the website below and rather than $100 or so each, both were $97, including freight. They are fairly easy to install (but somewhat messy). The only issues I ran into were that the old "O" rings didn't come out with the old hoses and I had to make a hook out of a wire and dig them out; also I found that it is possible to install the lower hose where the upper should go.
http://catalog.eautopartscatalog.com/
http://catalog.eautopartscatalog.com/