Well, N2 actually requires no modding.
CO2 runs at around 800-900psi
N2 runs at 3000-4500psi
Both fit in the same fittings.
The same Palmer's Regulator that handles the CO2 will handle the N2 and the output will be at the same psi.
Again, idk about the Escort's performance. However, MonsterAirsoft does make AK varients so if you take something like a G&P SVD and then replace the gearbox with a drop-in version from MonsterAirsoft and you won't need to bother with upgrading it yourself. And, since it's gas operated, it will last much longer than an AEG gearbox.
If you do get the Escort, you will need to tinker a bit with it, but it's easier to handle than an AEG. idk about MonsterAirsoft as I haven't seen the goodies myself.
Get back to us with SniperX's response, I'd like to see how far you can push an Escort.