A good (and relatively cheap) option is to get your standard units rebuilt. Talk to the fellows about what you want out of them and they should be able to set them up for you. Lot cheaper than a really good set of shocks, although rebuilding something over 20 years old may be a bit dodgy if its a very worn, high-milage example.
If in doubt I would simply recommend an aftermarket unit. Good brands include Koni, Ohlins and to a lesser extent Sachs (good, but not outstanding).
Cheers - boingk