that's exactly what I would do as well. make the sort of movie I want to see, THEN identify why that is and seek out the audiences that share those reasons. buddy of mine made a doc about mma fighter Jens Pulver. he crowdfunded the budget and sells dvds and downloads to mma fans.
I'm a firm believer in letting the fans pay to fund it. That's what I'm about to do with this fan film for sure, just need to decide on which one I'm going at.
Naturally, some niche's or communities will be larger and more receptive than others: an MMA community is more likely to actually PAY for content afterward, versus pirating, than a video game or anime community. Especially anime, which sort of lives on piracy for the most part stateside. Communities like these, you should get them to crowdfund the project so everyone wins.