Custom Format For the same I use as a filter

So I currently have a filter searches for Blueray, Web DL, Web Rip, 2160 and 1080. Then I sort by size and I manually download the lowest sized one, usually anywhere between 8GB and 12gb.

How can I automate this with custom format?

Multiple CF’s for different sizes and giving each a varying score, higher score for lower sized ones?