Joined just to opine here.
The best way to do this would be to make a buildings pack first. Right now, ARMA 3/ARMA 2 don't have a lot of Western styled buildings available. If one was to make a decent building pack, this could go a long way towards making Western maps.
For example, an American suburban residential building pack would be a godsend for this sort of thing. Even a generic pack filled with McMansions (two story homes that the upper middle class tends to live in), single story traditional homes, and small duplexes would suffice for now, as the "cliche" American suburb is mostly comprised of these sorts of buildings. If you want to go into more variety, small apartment buildings, trailer homes, garden sheds, and detached garages should also be included on the residential side. Commercial structures in suburbs tend to be franchised fast food chains, gas stations/car shops, banks, supermarkets, small mom n' pop shops, strip malls, small offices for professionals and of course some municipal buildings (schools, courthouse, water tower, etc).
There are also smaller assets that need to be made to avoid a feeling of sterility. Lawn ornaments and vegetation, furniture, signs as well as other props need to made or incorporated somehow, but I imagine this would be tedious, so the focus on such details shouldn't be an immediate priority.
Avalon in the Santa Catalina map sort of captures this environment very well, but is pretty sterile and has a sort of artificial appearance. But its a very good model to aim for, and should suffice for our purposes.
The prospect of a faithful ARMA 3 representation of an American suburb or small town is very, very appealing to me, and I imagine others.