Hey These are really good days, fairly quiet and @graeme4130 instructs. get in quick folks, i'm booked 6th and 31st May. https://www.silverstone.co.uk/track-days/bike-track-days/
You don't get to choose. You put in your "experience" and they select for you. However, in "notes" is asked for fast. It's a lot calmer than normal TDs like No Limits.