Does anyone know what physical dimensions would categorise a person for which type of aircraft?
Ejection seats have certain parameters, back length, leg length to the knee and from the knee to the bottom of your feet. If excessive will prevent correct operation and may even prevent you operating handles. If you are two short, there are issues with what is known as functional reach. i.e, you are strapped to the seat and cannot reach normal controls. If you are over 6ft 2 you could have issues but there have been aircrew up to 6ft 4, above that you will have issues and if you are under 5ft 5 you may have issues.
Some years ago I was involved in an anthropometric study at Farnborough, the range of different bodily dimensions that they can fit in is quite considerable however; aircraft are designed around a normal curve. If you have any dimensions outside the normal you may be restricted, too many dimensions outside the box and you will be excluded altogether.