Depends on how long you want your piece of string.
My 1996 4.6 has 120,000 and is going strong (still looks like new [on the outside[).
Like anything else the importance of regular servicing becomes even more so as mileage increases. The extra cost of 6-monthly visits to your local dealer is cheap insurance. Also it's probably worthwhile going with an extended warranty (as always(.
The 96,000 mile service is a must. Replacing all the rubber under the hood is a very cheap way of prolonging part life.
Known problem spots around the 100k area are the hoses (see above), the fuel pump (mine gave out at 115k), and the heat exchanger core (very wet front passenger footwell). Other than that my guess is that with a bit of regular tlc the engine block is probably good for 180-200k (if not more), and the body will last longer yet. I've not really seen any data on how long the chassi holds up, that really depends on how salty the roads get in winter etc, though looking at the UK classic population, I'd say 15-20 years of service shouldn't be improbable by any means.
HTH
Staffan Tj.