zoom lens

Following on from the popular threads Mobius Varifocal Zoom IR and Mobius 5MP Varifocal Zoom 6-22mm ƒ/1.6 both started by @Dashmellow, I was keen to try the new Mobius Maxi 4K paired with this 3.6-11mm 4K Varifocal lens offered by Fulekan via AliExpress. 8Megapixel M12 Mount Varifocal 4K Lens...

I'd like to use my Mobius to zoom in on some distant action (example: a person 100 yards away). I have no idea what focal length I should be looking to find, nor do I have any idea of a quality lens that includes the IR cut filter. Rather than spend hours prowling the web, I thought perhaps...