It makes no sense to continue it as copying the Arma II mod, it's not going to revive this mod in any way, there's other servers that done it and went nowhere, I have not yet to date seen any sucessfull servers trying to copy the Arma II UI, there's the russians who made TOP GTA and made it kinda similar but had the ability to drag the stuff into your inventory, there is currently a russian team making Standalone, and everything in Standalone, going as far as the first person mods.
Right now. For the Official Mta DayZ, the inventory is a complete let down and it looks ugly, no offence. It was inspired by the newer Vanilla updates, well a lot of people weren't actually satisfied with that either. Since standalone came out, it's became the norm for games to create a inventory system where you can actually organize your inventory, placing objects in your different clothing pouches. If you actually thought about this, and added it. Maybe some more people will take interest, because the current UI is a complete disaster, no offence again, the icons and everything are just stupid. It should be re-done in a more current day fashion, no matter what you say you can't justify it, like I said out with the old and in with the new. But I guess, since you're the developer it's going to be what you want anyway. I'd even offer to help you as suggestions and keeping you motivated to make it.