You will need a 6 point harness that is FIA approved 8853-2016. Make sure it is a single-seater harness. Popular brands are TRS, Willans, and Sabelt. Some cars have different connection points for the harness, to request different connection points you will have to email the harness provider.

Oliver uses a blue TRS Pro Superlite 6 Point Single Seater FHR Harness

The helmet is an essential part of single-seater racing as the only part of the body exposed is the head. 

The helmet FIA spec 8859-2015, and make sure they have the FHR (full head restraint) posts fitted. 

Oliver uses a Stilo helmet with is FIA 8860-2018 spec.

This needs to be FIA spec 8858-2010. There are two options – one that sits around your shoulders/neck, and one that goes over your race suit around your back/chest.  The ones for your shoulders/neck are set at a 20 or 30-degree angle, a 20 degree is generally if you sit quite upright in the Vee, whereas the 30-degree ones are better if you are a bit more reclined. 

Oliver has a 20-degree HANS device because he finds that more comfortable.