Hi Ark, just been down this very route myself.
I too did not like to buy off the internet as you do need to test fit for size. In the end I used a local bike shop and tried on many different types from £50 up to £250. As I only need it for occassional track use I opted for an Arashi, only cost me £50, fits perfect, has fully removable washable liner & is full face.
I think it is the "turbo".
I also phoned a few track day organisers (book a track, easy track, mithril racing) to check whether a ACU gold or ECE 22-05 type approved bike helmets would be OK and they all said yes.
HTH
Rich