PC or else?

[rmadrid20]

Well I want to buy either a PC or something else for this propose...
I usually download movies on my laptop and stream them with either roku in my room or chromecast in my living room. I dont want to uae my laptop no more so i need a device attached to my tv where I can surf the internet download theovie and watched there and share the file on my second TV, can in do that? What device I need, a PC? a mini PC? 2 of them, I don't know, need help please