The "Issues" tend to get blown out of proportion. The main one for the PD engine, the camshaft, pops up over and over but if you dig into it you'll find it happens more often with the PD engine in the Passat (thinner profile in the lobes) and almost always involves using an engine oil that can't deal with the pressures exerted on the cam. The other issue that pops up is the in-tank fuel pump failure. Its a pricey item but a fifteen minute repair. Diesels in general require more maintenance, using quality parts, specific fluids and extra care in doing that maintenance. You shouldn't take them to any old shop that services gassers (including VW dealers) especially for a timing belt change, which is why most of us do a lot of it ourselves.
In the 7.5 years I've been running my Golf with the PD I've had only two glitches that would be off routine wear and tear/preventative maintenance; that's the transmission solenoids and fuel pump. Solenoids will only affect an autotrans so if you find a vehicle with the manual transmission it's a non-issue. I've had wheel bearings go, the battery, the fuel pump, changed the timing belt twice, changed the transmission solenoids, shocks and struts, pulley on the alternator, upper charge tube. Yeah, it adds up but I'm not paying for labor. I'm no master mechanic but with the info and experience you can tap on this site, even a driveway mechanic can keep a PD running. I think the simple design of the PD makes it easier to service with fewer specialized tools but some people prefer the earlier models that have more options for modification. PD's have a bit more power. Just be cautious. A poorly maintained diesel can cost some money to bring back to good condition. And don't be shy about lifting the valve cover to inspect the cam and followers if you go for a PD. It's a deduct from the sale price if it's worn. If the seller tells you the t-belt broke assume you need to have the head rebuilt. Good luck in the search.