IMO there’s no “best” material, they all have advantages and disadvantages. PLA is very rigid, PETG is UV and temperature resistant, ABS is temperature resistant and dissolves in acetone… ABS is tricky to print though, even with an enclosure. I wouldn’t recommend it unless you need the higher temperature resistance or like to tinker.
LetsEncrypt is a good option if you want to set it up yourself. More work than cloudflare though.