Pcvr quest 3 requirements

So I see people saying they need a gtx 4080 or great to be happy for pcvr.. What am I looking at to get native looking resolution (can be up scaled within reason) on a quest 3 at decent frame rates (potentially with frame interpolation if needed)?

I'm hoping a gtx 4070 will be enough to be ok.. I dont want to spend more and not interested in a gtx 4080 super or 4090

I'm a little confused. Do I need 4k res to then upscale to the quest 3 at 1.3x, potentially having 45 fps generated by the gpu and interpolation will help get the smooth 90 fps required to not feel nautilus. I realise his may add a small amount of input lag but I'm not a competitive player.

I'm assuming 1440p isn't going to upscale well to the quest so I'll need 4k? I'm assuming interpolation to get the frame rate up 2x isn't too bad unkess you need the best with no artifacts?

I see people saying 12GB may not be enough vram.. But I'm happy to turn textures down a little to help if needed in some games.

I'm really after those that don't need the best to comment. I'm not an avid gamer and happy for the middle ground.