Newbie needs help building cinematic fpv drone

I didn’t notice any rules saying i cant ask for help wi this. Hope it’s okay!

So im completley new to fpv and I think it looks awesome! That goes for both the crazy cinematic shots and the experience of turning yourself into bird on crack. I think regular drones are great and this is obviously taking that experience to the next level.

My requirements:

i want to be able to take smooth cinematic shots while also being able to have some fun. Ideally i want a longer flight time. Im also planning to record and make videos with my friend who is into downhill and mtb in general.

How far i’ve gotten with research:

Im willing to pay 400 and i’d like to build the thing myself. But if there are some good prebuilts you know of feel free to recommend them.

from what i gather i would either want a 6s cinewhoop or 4″ drone with a 800-1000 mAh battery. Is that a reasonable assumption? Which is best if so?

My question:

What kind of drone should i get and what should i be on the look out for when choosing parts? (taking my needs into account).

I have a souldering iron and very basic skills when it comes to using it. Could i manage building a drone myself? It doesn’t look like it would be much more advanced than building a pc to me… Also is 3d-printing my own frame a good idea? Polypropylene is supposed to be really good for drones.

Edit: i want a digital hd drone