Am after a MK5 Golf preferably a 1.9 diesel Sport/GTdi

Are these good reliable cars ? Any known major problems that i should look out for ?

Am looking to spend about £1000 for a 2004 150k mileage.

Is this a realistic figure for a decent golf or should i be looking to pay more or even a MK4 ?

Also some are listed as PD engines and others as TDI. Is there any difference ?

Do the 1.9 come in a range of BHP or are they all the same engines but with a different map on them ?