I've decided on a spot in Hamilton's Hideaway (not the cache that's locked). Since the ACRs are in the leveled lists and at vendors randomly (through scripts of course) there's a chance you might get one before you even reach there. All the upgrades are randomly available though so going there will guarantee you every upgrade.
Any plans for a Unique variant? Maybe, instead of a Unique variant, make Unique parts that are more effective.
That's not a bad idea for unique parts actually, I'll give it some thought on what they could be. As far as any unique variants go I still did want to try to make a camo version of it, though to add a new version like that requires a fair amount of scripting to get it to actually work properly. It might be easier than I think though so I'll have to play around with the idea. Plus because of the way I unwrapped it the camo would look off in certain spots.
EDIT: I've just had a great idea. Instead of unique variants, how would you feel about swappable paint jobs? I don't know if I'd include it with the initial release but definitely later on. I was thinking of an urban pattern, a desert pattern, and a woodland pattern.