Just to add to these comments about favouring gas over diesel, one thing I've not seen mentioned is the poor range and loss of a spare wheel (assuming the tank's in the spare wheel well of course).
This was important to me and pushed me towards my first diesel LR of any description, as I use mine exclusively for longer trips and the 500 - 600 mile range (at 30 mpg plus) is really appreciated.
I would make sure it is auto and chipped (most seem to be now) though, else the performance is dire.
As to faults, well check for water loss or other cooling faults, check everything electrical works including the AC, there can be some rust but most late 90's ones seem OK yet. Most of all, make sure it's been looked after properly, as this is a vehicle that will really bite you if maintenance is skimped.
Finally remember that they are cheap and plentiful, so don't buy the first one you see unless it's really good.
Cheers
AWM