What kind of audio gear to make a movie with GH2

[Obscure]

Hello Andrew and everyone here. I've just become a member here but I've been visiting this site for about a year. I'm interested in GH2 more than any dslr video camera though i had wanted to get a canon eos 7D before I came to eoshd. I heard about 2 feature films made entirely on eos 7D, 'Love Crazy' and 'Tiny Furniture'. I don't have any camera right now except a kodak p880 bridge camera which doesn't work properly anymore. I don't have almost any experience about shooting a video with any camera that offers 2k video with manual controls but I've been reading books, magazines, articles on websites and been watching videos related to cinematography, still photography and any aspect of film-making. It seems I'm deviating from the main topic and I don't know if this is the right forum to post this topic. Well my question is what kind of audio set ups will I need to make a short or even a feauture movie with GH2? I'll get a GH2 soon or maybe a GH3 if it comes out soon or any hdslr camera that offers better performance at the time of buying without having to spend more than 2k$. But I don't have any idea what kind of audio gears will I need and how much will it roughly cost. I'm from Nepal and I can't afford much. Is it possible to make a feature film with gears not costing more than $4000? A feature film that can be showed in film festivals like sundance, cannes etc.? I don't have much idea about the lighting either. I read in American Cinematographer that Malick's 'Tree of Life' was mostly shot in natural light. I'm thinking something like that. Right now I have to think of what I can do with the gears that cost around $4000 rather than what gears should I get to achieve what I want. Forgive me for my English and the way I have written as English language is my second language and I'm not fluent at it. Thanks in advance and thank you Andrew for this website.