I wear a Giro Seam and it is light and great for ventilation. Relatively low profile, but I think there are better in this regard, however, any of the really low profile helmets don't seem to have manual ventilation options. So, a trade off.
If there are no stores near you, I'd order one helmet from several manufacturers that you like, try them, and return the others. Do it all at the same time so you can compare directly. The fit from different companies can vary significantly.