I've got a 2002 TDCI ghia 130 ps. Great car. I'd go for it.
Check what 1992lp said and in addition:
I'd check the various pulley's and belts though, they need replacing at about 70,000ish. If they make a funny sound when the engine is running then they may need replacing soon. The last thing you want is one of the belts to snap with the engine running.
Make sure when you see the car it's started from cold, some will cut out when the engine is cold, or the glow plug light will start flashing and then within a few minutes the engine will cut out. Could be a few things causing it, some very easy and cheap to fix, some costly.
Go for a fairly high mileage one, it would have been used mostly on motorways which is better.
Don't worry if under acceleration it belches out some black smoke, the egr valve just needs cleaning (it gets blocked with carbon deposits, totally normal)
It's a great car to drive though, nice responsive steering, and rewarding handling for the size and class. Very spacious too, and its well put together, very very comfy too. It's pretty much a tank, would much rather be in a Mondeo than a small eurobox. Huge boot. Great cruiser. Go for the 130 ps for sure, lots of power and very accessible, overtaking is pretty easy.