Zetec is the 4. Honestly, I wouldn't recommend a Contour to that many people, but if you like sporty handling and don't care about acceleration, and the price is right, the 99 might be good. Give us all the details and we can help you decide.
How much do they want?
Is is auto or manual?
Do they have maint. records? If so, how was it treated?
What options? Sunroof, alloy wheels, etc.
Also:
What do you want it for? Cheap commuter, ricemobile mod car, etc.
What do you expect in a car? Sporty, luxurious, reliable?
How long do you want to keep it?
Do you plan on working on it yourself? (I guess not, from your posts)
If not, do you know who would work on it for you?