Well, 2 IPC Infantry seems kinda pointless, if you can just get an Elite for one more IPC. Unless you rendered elites like around 5 or 6 IPCs, I do not see much good coming out of 2 IPC Infantry. I have never played New World Order, so I may not be neccasarily correct, so by all means please give me an example how this could be successful.
Another point to touch on is that Elites should be exactly what they sound like, Elite Infantry. Therefore I think the Elite could easily fill the role of both paratroopers and marines. By being Elites they are air transportable, but also do bonus attack (or whatever marine units special ability is, I seem to have forgotten it) in an amphibious invasion.
With the Elite unit Im unsure about artillery now. I think that artillery should cost the same actually, and support 2 Infantry. Maybe, maybe not. My only confliction is I dont want these units interfering with the light tank unit or the truck/ mech inf.
So heres my summary: Inf 1-2-1-2
Elite 2-2-1-6 (Air Transportable, Marine capabilities, etc.)
Artillery 2-2-1-4 or 2-2-1-5 (Supports 2 Infantry, or has like an opening fire step,or somthing)