Anyone suggest a size for T2 AGV? and a visor question

Hi guys, my head measures up as a large 59cm but nearly every helmet is a medium 57cm for me. Salesman at the biggest shop in town and one at another store both told me I'm a medium size. AGV K3 is a medium for me with just a touch of movement if I shake my head vigorously, and so is a Shoei Quest, and a KBC VR-1X. Nitro Aikido in medium is too small??? Shark S600 is good in medium but chin bar is quite close. SHARK Vision R is a medium. HJC IS-16 is good fit in a medium, but the CS-12N seems too small in a medium! So whats your best guess on a AGV T2 for size? My personal preference is for lightly firm to ideal fit, not loose, more like a glove not a worn out slipper. And do other visors OE or not, fit this helmet as I would prefer something tinted without tear off posts. My riding is commuter and pleasure/short tours. Upright style, not cruiser but not tucked. Let me know if this is a bad choice in lids for this purpose. Thanks everyone.