Poetpilot - just curious as to whether its G-AYSK you're flying? I used to to have a share in it myself a few years ago. Flying it off the beach at Middleton Sands was great fun! I cant offer any advice on helmets I'm afraid, I just had one of those cloth helmets with the holes cut in the side for the earpieces of the headset. It worked fine for me, though most of the time I just trundled about non-radio.
Have fun in it!!