2005 tdi wagon injector nozzles

I am trying to locate a how to or injector sizing guide on injectors for my bew engine. I want to know if its even possible to change the nozzles on this car and if its worth it. I had an ALH and never got to doing it. What are good nozzles? Best place to buy? What tuner to use with them. Malone or Kerma.

You'll be fine to run the stock nozzles on a stock turbo or VNT17, they flow considerably more than the VE units did.