Always wear torags, Ahrims is a plain waste of dead weight. Mage Bonus doesnt help much at all against the melee brothers, so as long as your mage bonus dont fall below -15, then you are good to go. I would personally suggest verac's armor tho, the brassard has next to no mage penalty (-6 instead of -30), and has a substantial prayer bonus. If you cant afford the entire armor set, certainly try to buy Verac's skirt. Cheaper than T legs, less weight, equal melee bonus, no mage def penalty (at the cost of 8 point loss in ranged def) and has +4 prayer bonus. Definitely worth the money