During at least part of that time he would've worn his uncle, Guillaume de Tancarville's arms as he was part of his household until he was belted. He would later go on to his uncle the Earl of Salisbury's retinue, for a brief time and so would've had his arms on his shield and surcoat. I don't think that he had the red lion rampant on the green and gold field until 1180 or so?
His entire harness would've been all maille- a full hauberk of riveted links to the knees with an integral coif and mittens most like; perhaps maille chausses as well. A conical or nasal helm, probably the raised, not the spangen type of the earlier Norse would've been his 'workaday' helm; there's record of him having to have a blacksmith essentially pry a helm off of his head which would suggest an early barrel or pot style helm that was more or less fully enclosed during his tourney days.
I found The Greatest Knight by Elizabeth Chadwick to be just as awesome, if for a slightly different reason.