Well the helmet arrived today and its a thing of beauty. Red visor modified by 501st member, and it has two fans that blow out nicely to stop wearer from heat exhaustion. Very happy with it. I can wear glasses underne3ath quite easily too so perfect fit for me.
AUSSIE AOTC ROYAL GUARD: Raising the forcepike in Tasmania
Depending on how much room there is with your glasses, might want to consider the sports wrap around glasses. Like the ones you see basketball players or squash players wearing. There are lots of place online, and they are much closer to your face which gives you more room if you want to shift your head a bit. It also has much better peripheral vision, and won't shift around if you nose gets sweaty.
Not a requirement, but figured I'd pass it along as something to think about.