Ehhh.. I spent a couple hours looking a few months back, there are a few still made, your best bet is to buy a nozzle made for a water (blue) jerry can, they definately still have the old top.
I'm sure you could also find some PVC pieces at lowes, do some magic and have one (then paint) Or find a metal nut (Biggun) and weld a spout to it and put a rubber seal in it (Of course these methods are extremely unlikely and pretty crazy)
But yea water jerry cans are a good bet, Just buy a replacement top for one and then buy the one you got listed