Boost Pipe Oil Leak

I have a 2003 150TDI with 149,000 miles on the clock. I have had the car almost from new, in fact I got the car when it had just over 10k on the clock. The car has a full and thorough service history. Whilst the car was in warranty everytime I had it serviced I was told that the turbo was leaking oil and subsequently they replaced oil seals, this happened at least 2-3 times before the warranty expired. Since the warranty expired I was always advised about leaking oil seals on the turbo but I never forked out to get them replaced. But now I am getting oil leaking from the two lowest points of the boost pipes (bottom of the engine bay on each side of the intercooler) My boost pipes are the type with barbs and spring clips to secure the pipes. As the oil is now leaking on the driveway and my oil consumption rate has gone up I think I should now try to fix the problem and reduce the amount of oil going through the intercooler system. Does anyone have any clues as to what seals are the common ones to leak? and are they hard to replace?

Whilst on the subject does anyone know of an aftermarket kit of intercooler pipes? At least two of mine are now broken but I have managed to secure them as well as the original fixings but am quite keen to replace the entire set.