Hello,Dear Paul,my honor my pleasure to talk with you.
Maybe you might never hear about this brand,but i can speak loudly most of the camera can satisfied your requirements easily.
Just see this one normal camera model as below,check the specification, almost match your every requirement!
1/2.9" SONY Low Illumination 2.4MP CMOS Sensor
HISILICON Hi3516C, WDR; External POE +6USD
Main Stream: 1080P/720P@25fps; 3MP HD Lens, With IR‐CUT(Night vision)
Vandalproof IR Dome Camera
NEW IR LED: 14μ x 18PCS
IR LED: ¢5 (12μ) x 24PCS (Optional)
IR range: 20m
Board Lens 3.6mm/F2.0
Add USD0.8 for 2.8mm Lens
Blue/Orange/Black Rubber Ring
Size: ¢94.5 x 76(H) mm
Weight: 450g
As for the broad of Lens i would like add a illustration for your reference:
Oh, i don't know how to insert a image here,sorry!