Blackmagic is great for films. Personally I think video autofocus is useless unless you're a YouTuber or something like that. The best codec for the money comes from Blackmagic RAW, and therefore the most latitude in post-production. If your budget allows for the X-T3 like >>3579185
says, that would also be a great choice, but it won't beat Blackmagic's codec for color grading, not even with an external monitor. The X-T3 records 10 bit 4:2:0 internal, by the way. To get 4:2:2 on the X-T3 you need a monitor and it's still not great compared to Blackmagic's 12 bit full color space (chroma subsampling doesn't apply to RAW footage) But bear in mind, both are much better than 8 bit DSLR footage both straight-out-of-camera and for grading (my video camera, the G85, only shoots 8 bit.)
You might want to invest in a gimbal, depends on the shots you want to achieve.
Putting time into the storyboarding, and using extra money for lighting, sound design and props/set design will make you very glad to have whatever camera is in your hands. Color grading tutorials online should tell you everything you need to know, it's really not rocket science. But yes, a Blackmagic will give you the most bang for your buck in getting the "film" look while not needing to worry about pushing the colors too far.
Make sure you have enough money left over for good lenses, unless you already have some. In video and film, the things outside the camera body matter more than the things inside. Remember that Upstream Color was shot on a hacked GH2. A GH2 is dirt cheap now and the hacks are free, you can easily save lots of money to use on other aspects of your film, depending on what you want to produce (4k vs 1080, MFT vs APS-C or Full Frame, etc.)
Have fun and God bless anon!