Hi,
I've just done similar on my 200Tdi 5-door Disco.
Rear springs changed for Heavy-Duty types (camel trophy spec), front springs changed to heavy duty spec. All four shocks changed for Pro-comp ES9000 gas struts.
I am very pleased with the results, and the springs are cheap as chips
- all Britpart, no problems yet, but i haven't long done it. The shocks are pricey though, at about =A335 each, but i swear by them (used them on previous vehicles too.)
I guess it depends on your budget, and what you are trying to achieve. I tend to throw my disco around a bit, so prefer tighter shocks. I also tend to carry a reasonable weight in the back on a permanent basis (100-150Kg) Thats without passengers, but i rarely have them. I have a winch and 2nd battery in the front too. The new springs and shocks are a BIG improvement over my standard items. BTW, both my front and rear anti-roll bars have been removed.
I can dig out part numbers for the springs if you wish, and prices/suppliers. If you intend doing it yourself, i'll post some tips ive learned along the way! :-)
Sorry for the long post,
Chris