I am biased against VW products as I currently run a Passat 2.0 TDi PD. It has proven to be expensive to maintain and it's nowhere near as reliable as I imagine your earlier one to be.
The Ford 1.8 TDCi is a well proven car now, it's been around since 1998 and the TDCi engines joined the lineup in year 2000.
4000 Euro should give you a choice of plenty of desirable vehicles. It's always a bit of a gamble buying used cars and it's important to buy with your head, not your heart. A Nissan Almera is not exciting to drive, for example, but it probably will never go wrong.
Let's have a look around and see if anything else appears that might fall outside the mass market radar.
Are you LHD in Macedonia?