Should I download video size to match Premiere's canvas size? Or is higher better?

[AnotherMe]

I hope my question made sense. I am going to download free video that is good quality. When I download the video, should I downlad the highest size and import it into Premiere Pro? Or should I download the closet size for the screen size of the video? 
My apolgies if this question was not written out clearer. I have some cathing up to do....

[Kevin-Monahan]

AM,

Good Q. For the original source, I always get the highest resolution and best quality codec as possible. Create editable clips with these masters in Media Encoder, or you can use your computer horsepower to manipulate them in the timeline if you are in a hurry or don't like that workflow. I prefer to edit with files that are not in the H.264 codec. 

Kevin

[AnotherMe]

Thank you Kevin.