@Stommytommy, first off all its rather depends on personal taste, VR/monitor setup and if your rig can handle the mods at full settings. Personal, (so in my case), I do hate seeing 2D trees, cardboard spectators, flattened car interior (in VRmode) and shimmering/jaggy mods. While I also think on the other-hand, it has no sense in running a great detailed track in the lowest settings.
And I’m not an hill climber, as an only in VR, racer, I’m getting sick while driving an hill climb.
But seeing this video below, could give you indication of what I think could be the best Hill climb track.
For cars it could be helpful as an starter to check RustyChest goodmod list
https://github.com/RustyChest/list-of-assetto-mods/blob/master/good_mods.md#paid-mods but keep in your mind this list is not the holly bible on whats good or bad. As for a sample I do not think he did any realtime ingame judgement! Especially in VR and lots of mods are very flat in VR. I would only skip old or not recently updated mods (Avoid mods from 2017 or earlier). For the rest its all about trying, which mods suits you the best!
edit: I do hope you do have an handbrake gear, as this brings more fun in driving.