For young boys (6 to 10): The Squires of St. Michael
For older boys (10 to 18): The Knights of St. Michael
For young ladies (6 to 10): The Handmaidens of St. Gabriel
For older girls (10 to 18): The Ladies of St. Gabriel
That's good. The Holy Angels would protect and minister to this order, and the knights and ladies would have them as thier models and guides. But I think it would be better to raise the age of knighthood to match the first year of high school, because this is where we first meet the most serious challenges to faith, when they want to teach us evolution and other humanistic ideas and the pressures of the passions become more powerful. That way the youth would know he/she was ready to enter a new level of expectation, and a more serious battle against the spirit of the age. By being set apart, as Christians should be, it might also give them strength against the peer pressure that really ramps up in adolescence, because as knights they would be special representatives of True Orthodoxy. There are lots of sins and passions that are introduced in youth like gossiping, laziness, man-pleasing and these could be a focus of the prayers and duties unique to the order.
Perhaps levels of achievement could follow the 9 spheres of the angelic hierarchy:
Knight, Lady over 18 -
Seraphim
Cherubim
Thrones
Knight, Lady up to 18 -
Dominions
Virtues
Powers
Squire, handmaiden -
Principalities
Archangels
Angels
I also think it should be somewhat secret, not an obvious or outward thing. There should be medals and badges and group works and activities, but the knight, or lady, should be somewhat hidden and covert when apart from the group. Fight fire with fire.
There should be a special vow to always speak truth and seek justice in all things and never to stand for the dishonor of Holy things or any kind of blasphemy. Perhaps the ladies could read a cannon to St Gabriel and the knights a cannon to St Michael once a week during the fasts, and they could earn a badge for that. A shorter prayer to each perhaps for the squires and handmaidens.
The original chivalric orders of the middle ages were formed to continue the fight against Islam and the Ottoman empire after the failure of the crusades. and the fall of Constantinople. A new TOC order would be more focused on the battle with ecumenism, apostasy, and the anti-patristic spirit of world orthodoxy. It would be a kind of crusade to reclaim the Holy land of those Christian souls in the mason/illuminist occupied territory of the world churches. But there will be trouble due to disagreements between various TOC churches I expect. Maybe it could be for any Orthodox Christians but based on resisting modernism and ecumenism etc. Stay independent of Jurisdiction.
Special attention could be given to Soldier saints like St George and St Demitrious, and Monarch saints who fought great battles like Saint Prince Lazar of Serbia or Alexander Nevsky and The Royal Martyrs. Many Fathers used a military analogy for the spiritual warfare, perhaps a small book could be compiled from these teachings for the order to study.
Couple of quotes from websites:
The nine cardinal principles expected from Chivalry are those of loyalty, piety, frankness, bravery, glory, honor, contempt of death, helpfulness towards the poor and sick, and respect for the Church.
According to belief, Christian chivalry began with the Emperor Constantine in the Fourth Century about A.D. 312. This is attributed to his vision of a flaming cross in the sky - that of the True Cross of Christ - on October 28th, A.D. 312, just before he rode into battle against Manentius. In this vision he also saw the words "In Hoc Signo" meaning "In this sign you will conquer." Constantine was victorious under this sign and the first Christian Empire was founded in Byzantium. The fifty warriors that he had selected to carry the new imperial banner that contained the cross became the first Golden Knights. They were organized into what was called the Sacred Knightly Guard, also known as "Torquati" (Golden Knights) and "Perfectissimi" (Most Perfect Knights).