The OMP RS-PT2 is our most popular seat with Head-protection.
It is suitable for "Mr average" - it is a good sized seat with deep sides (So suitable for smaller competitors) This is a seat we have used ourselves on the RAC rally, reassuing its comfort.
This seat is side-mounted and has covering across all the side and rear.
Why do we like this seat? - its narrow shoulders mean it fits most cars. The head protection is discrete, a lot of competitors actually look over the top, but feel the protection around their cheek area.
If you want something narrower - try the Sparco Circuit. For something larger - the Sparco Circuit 2.