You absoloutely don't need a mace. Firstly, I suggest starting off as a Dark Elf or High Elf since they both have advantages when it comes to arcane mastery. Secondly, you should really be using a light armour or robes. In my opinion the best robes one can get are the Arch-Mage robes from the college of Winterhold questline. When you complete it, you will recieve them along with a few other delights. Also, train yourself if destruction magic. I tend to use fire spells a lot and have all my destruction spells perked to level 100. If you're bored of using just magic, then I suggest you seek out using one-handed weapons. I tend to use the Ebony Sword or the Dawnbreaker (Daedric Artifact) since they're decent enough weapons.
I really wouldn't suggest using staves other than the Wabbajack or the Staff of Magnus since the others are pretty much useless compared to using the exact same spell just only using magicka and not having to refill with soul gems. If you really want to use staves, I suggest you seek out the Black Star/Azura's Star (Daedric Artifact)
With all of that taken care of, I can kill elder dragons in 4-5 shots from the fireball spell and it only drains 1/16th of my Magicka bar (estimate) and my defense is pretty damn good.
That's pretty much it. Have a fun time playing
