Have you pulled the fuel flow pipe off the metering head via the banjo bolt? It should be under pressure, and when the pumps running, should piss fuel out. If it does, that proves the system as far as m/h, then its time to pull an injector(s) to prove flow. If none, work your way back, ie disconnect injectors from fuel lines and check for fuel there. You will need pump running and to lift air flap, this process is on here somewhere, have a search. Regarding fuel filter, any pattern one will do, its not got to last that long, as you should change it every 1/2 years. I used vwspares.co.uk for mine, was about a 5er, and was made by mann filters I think, which is a perfectly good enough make.