Great input thanks. I have CO2 and Beer Mix already. The nitrogen tanks share the same threading as beer mix. Nitrogen / beer mix regulators also have to go to 3000 psi or more since its a tryue compressed gas not a liquid.
From a wine dispensing perspective argon is best; it's inert, doesnt dissolve, and is denser than air so it displaces any residual oxygen with an Ar blanket on the liquid surface. Nitrogen is a close second best save for the density. CO2 is denser so it blankets but it dissolves. Beer mix at low pressure would address the density issue of nitrogen, but over time the CO2 will dissolve. I've seen suggestion of initial purging with beer mix or CO2, then pushing with nitrogen after that, since argon is rather spendy.
I have all the hardware for nitrogen, it's just a question of whether it's worth the effort and cost of a third gas cylinder, or if I'm just getting carried away and forgetting that I'm just a lowly homebrewer!