Paladin would be easiest. For DPS, Black Mage wouldn't be bad.
For low level macro single target:
Raging Strikes
Fire x5
Transpose
Ice x3
Transpose
Medium level single:
Raging strikes
Fire 3
Fire x4
Blizzard 3
Blizzard x2
High level single target:
Raging strikes
Fire 3
LAYLINES
ENOCHAIN
FIRE 4
FIRE 4
SWIFTCAST
FIRE
FIRE 4
FIRE 4
FIRE
BLIZZARD 3
Blizzard 4
Repeat until ENOCHAIN cool down is cleared.
You can throw in quelling strikes from archer as well to help lower your hate generation.
Type while you let the macros do their thing.
For those that think I should've put in more casts, I prepaired for when LAYLINES runs out so that you're already compensating for a slower cast time. Also, ENOCHAIN and Raging Strikes stack. I use the combination all the time and get +25% damage.