MrChipShoulder,

For me, I would have :

#1 Centra 1.8 Crystal https://www.intershoot.co.uk/acatalo...-Iris-431.html

#2 Centra 1.8 Basic https://www.intershoot.co.uk/acatalo...-Iris-644.html

I doubt whether you would ever need an aperture greater than 1.8 mm.

Have fun

Best regards

Russ