Good wizards are awesome. Are you a good wizard? Most aren't. :/
As for gear, grab mana items. Some would argue that mana doesn't matter, only mana regen matters....but they aren't the ones that you'll be grouping with anyways so screw those guys.
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They aren't about sustained dps. They can offer a lot to a group though. Can help cc, blow up casters, pick up/evac groups, etc.....
Or you can waste mana on useless crap and go afk to med like most... (hopefully not! )