Just my penny worth of info.
Do you want a Sportwagon (estate) or a saloon? I have driven both and IMO I feel the saloon drives better.
Engines - Petrol or diesel? If it's petrol then I would go for the 2.0 TS -I had a 1.8 and it was great but a little more power from the 2.0 will be better - fuel economy isn't bad for a 2.0 (I can't remember exact figures, someone will know).
Diesels - the 2.4 JTD is the one to have, they come with various bhp outputs however depending on the year of the car but basically from 136-175bhp. Economy is very good on these cars (so I am told) and performance too.
If you are buying a petrol make sure the cambelts and variator have been changed every 36000 miles/3 years and check for a FSH. The cambelt is very important to get done.
Again on petrols the oil does need to be checked every week and topped up.
Handling of the petrol cars is
- almost go kart like! The heavier 2.4 JTD suffers a bit from a heavier front end but is still a fine handling car.
Make sure you go for a Veloce (sporty spec, side skirts, nicer alloys, lowered suspension) or a Lusso (leather, nice alloys) spec. Turismo is basic spec.
There is plenty more I am sure but that is a start
Best of luck hunting one down