How many miles on the stock engine? cam should not be going flat form normal wear. my 360K mile AHU's cam is only worn down by about 0.0018 from its original size.
Something is not right and you need to address why its worn down. Stock TDI's usually run stock internals and cam and can go 600K with out thinking about it if cared for properly.
If your just replacing parts, sure the cam is a fine upgrade. I would suggest a vtn17/22 hybrid for a fairly stock upgrade.
When you say, its leaking oil, what do you mean? Out the exhaust? into the intake/boost piping? If its in the boost pipes, you can measure how much comes out. if its only about 1 cup-ish your fine, thats normal.
What did your cam measure out? A regrind is probably your best option from Kerma.
If your turbo is indeed fubar and so is your cam, i highly suggest talking with Kerma and getting a regrind stage 2, some .357 nozzles pop tuned, and a vtn17/22. Tune from malone or kerma
This is a fairly tame build and should last a very long time with reliability to boot. You might want to get a upgrade on the clutch though in the future before you go any further. 2.5" exhaust is fine
The reason i say do the nozzles and what not, is your tune is going to cost you a fair amount of $$$ and nozzles are cheep. you should only have to do a tune once if your on a daily or budget. If you do not do a tune you can run all those mods with no issue what so ever and still see a good bit more power. there are self tunes you an do to get more fuel for the turbo but if your going to buy a tune, do it once