I just want to mention that if you are using a HANS device, you will need the Quickfit PRO, which is designed specifically for it.Just to add - if you use a harness it's strongly recommended to use a HANS
Standard seat belt allows you to 'roll out' and reduce head momentum
Love my quickfit, but with a heavy helmet on and shoulders locked in - I love my HANS more!
That said, this being a "Novice trackday advice" thread, I would say skip all this and stick with the OEM seat belt and focus on the line and your surroundings. Learn to drive the car "as-is" first.