Class selection advice, please (for the indecisive min-maxer)

[Troxx]

If wizards had a fairly fast casting nuke (being a blue to cast and then sit again to hit Med ticks) that was hugely efficient mana wise but for relatively light damage ...

... that would have helped them out immensely. Such a nuke would be less than ideal for a hard burn but would have allowed them to sustain solid damage over time.