The Mage: Alanus Scotus, a grizzled old Scots clerk and hedge wizard
The Companions: Margaret May, a.k.a. Maggie Leech, a woman doctor/midwife from London; Usa'mah, a mysterious Saracen who was Alanus's guide to Baghdad and the secrets of the Caliph.
The Covenant: Preferably Summer. Alanus is getting on in years, and I don't get the feeling that he'd enjoy meeting in darkened street corners, so a building of some sort is in order.
I'll post more as I learn about these individuals.
Rob