IIRC the 16v K-Jet line is the same as the 8v line. The part shouldn't be obsolete - I bought one about 6 months ago! Its a single piece from the filter to the connecting link just out of the chassis leg. I tried to bodge one when mine broke - but the pressure is pretty high so it popped off and leaked frequently, I tried sourcing bits from elsewhere, but because of the connector on top of the fuel filter, the only way to go was OEM.
I would double check again mate, sounds like the dealers got their hoses crossed.