Good to know. Thanks for that info.
Ultimately, a cinematic look comes from multiple factors - frame rate, lighting, shot composition, depth of field, and content (to name a few of the major factors).
The #1 way to achieve a cinematic look is to shoot in a 24p/23.98p frame rate. If you really are looking for a cinematic look then (in my opinion) there is no other frame rate option. It's super psychological and essentially comes down to how our brains have been trained to view content over the last 100+ years. You can basically have everything else (cinematic lighting, composition, depth of field, etc.) but shoot and deliver it in a non-24p frame rate and it probably won't have the effect you expect. If you've ever seen cinematic dramas in PAL formats (25 or 50 frames per second) or cinematic dramas shot for daytime television (soap operas, for example), then you'll get the idea of what I mean. It doesn't feel the same as something shot in 24 fps. So just something to keep in mind as you go through this process.
Now, if you really want to stick with 30 fps then I would say you'll possibly get the most bang for the buck by investing in a lighting upgrade and adjustments.
But at the end of the day, the Hitachi HD5500s would be a natural upgrade. I would also suggest looking into the Sony FB80.
The Blackmagic URSA Broadcast is definitely an option, but there are some "gotchas" when it comes to them. One of the biggest ones is the full f-stop of light loss you get from the optical converter required when using B4 broadcast lenses. So if you're struggling with low light now, you potentially will have the same (or worse) results with the Blackmagic URSA Broadcast.
Do you have any video examples of your current setup that you can post? That may help me get a better idea of what you're working with and some steps to take.