Helmets & Helmet Suggestions

I have always used cheap helmets, the best one I've had was Kask Vertigo that I bought new for £70 .. it was wrong size, I needed a large, since then I downgraded to Rapido which was £45. Its comfy but the issues I have are:

1. Its bulky
   
2. Somehow fucks with the arms (?) of my specs (rapha) and sunnies (Bloc). They dont sit well at the back end. I had this issue with Vertigo but it was much worse as it was wrong size.
   
   

Given my head shape and size and having tried diff brands in shops I have to go with Kask and Large. Will Protone solve these issues? The most compact I've seen is Mojito.