Gas diffusion through bottles is the ONLY reason to transfer stuff to glass. LDPE for example is completely unsuitable for storing developers, but HDPE and PETE are fine.

Nitrogen (N2) is quite unreactive, certainly as far as photo chemicals are concerned. Seriously, no one is going to do a better job of packaging chemicals than the factory, unless it's those Digibase lids that would fall off in transit.

If you're gas-filling at home, hydrocarbons (butane lighter refill) is the easiest option. Heavier gases are better though and I think Protectan is something like a CFC.