Having played all tanks in MoP except brewmaster I'd rank them thusly:

1: Paladin--great AoE. Good damage or off heals depending on which you need--easiest to macro for me.
2: Death Knight--it's like the pally with spikey mitigation but does a bit more dmg.
3: Druid--gives crit buff, has charge and good dmg. Hard to use tooth and claw procs in macro.
4: Warrior--lovely tank if you always lead from it, but since I am mostly leading from my hunter I don't like it. To hands on to slave well with jumps and intervenes. Also hard to use certain procs because the nature of rage. (Don't like that about Druid either)

you really can't go wrong with paladin or DK, Druid and warrior work fine also--I used to really champion my bear until I started using the Paladin.

as far as your caster, have him follow-make a button to have him follow/break follow (quick step forward) and you can easily turn him to face your target and pick him back up. I 5 box tsulong and ill have my hunter and healer behind sunbeam and will move my hunter forward and hit follow and the melee will run to him to clear debuffs,,then return to DPS and ill just step back with hunter. You'll become quite proficient at all that as you practice.