if it’s interlaced video (the source), I would recommend starting with Dione:DV AI.
if it’s progressive scan, try Proteus.
you can give those presets a shot.
don’t try upscaling the entire video just to find out which one works best for you, it will take you ags…just run a 10-15 sec preview on a selected scene or number of scenes with different AIs and then compare the results.

you can use the Video-Compare tool to help you see the difference between AIs/Preset you use.