What indexers do you have added to sonarr/radarr? dbzer0 doesn't mind naming them afaik so you're good to share them here
Setting the quality slider as the other user suggested should work. Go to Settings->Quality and slide the size for WEBDL-1080P and BLURAY-1080P to the size you'd prefer (remember that it's defined as size per hour and not total size of the file)
The best way to do this imo is to define release profiles based on groups. I'm guessing, based on your size preferences, you'd normally grab H265/HEVC 1080p releases re-encoded by various groups like TGx and PSA

On Sonarr (v3), create a release profile and name it whatever you want. In the Must Contain field, paste this -

/^(?=.*(1080|720))(?=.*((x|h)[ ._-]?265|hevc)).*/i

This will force Sonarr to only grab releases which are HEVC. This is actually supposed to go in the Must Not Contain field because re-encodes are much more inferior. But if your intention is to save space this works.

Then in the preferred section you can define the rankings for certain groups you'd like to see. So type in -PSA on the first one and give it a score of 100. In the next one type -TGx with a score of 95 and so on with the groups you'd like to see with corresponding scores according to your preferences.

Radarr is on v4 and now uses Custom Formats so read https://trash-guides.info/Radarr/ to get a better understanding. The Sonarr section can also help if you want to be more specific with your filters. Anyway, Custom Formats can be imported pretty easily but its best you go through that yourself and try to recreate the profile we made on Sonarr for Radarr