A newbie level 88

Hello all,
I want to build a good mage so i need good stuff !
I dont know whats will be good for my mage and what stuff i have to use ?
I already got a mace of destruction and fire staff, i have a magical device to !
So i have some questions :
Whats stuff will be good for a mage (armor? Helm?)
And how can i do strong attack? I seen a video of someone doing 20k damage and i want to know if i can do it to haha ?
Thanks for your answer and have a good day