Helmets & Helmet Suggestions

MET Predatore is good if you've got a big head. Winstanleys has one going for £45.

Well this did it's job but now I need a new one:

That's a Giro Savant, which I bought because it was about the only one in the shop that fit, I have a big head. But I need more air flow next time around. I very nearly didn't wear a helmet that day because it was so hot. Wouldn't be here if I hadn't though.

What can people recommend for maximum airflow? Around the £100 mark.

I'm obviously now quite keen on Giro, but I also like Met and Kask. At the moment I'm looking at the Giro Ionos and Atmos - I love the Aeon but its a bit too pricey for me.

I haven't seen Kask helmets anywhere, and I don't buy anything without trying it on first. Who stocks them?