Which Flavor of Pally for 4x Shammy +1 Pally?

Hey all, I'm new to multi-boxing and have to say, it's amazingly fun and definately a big change from running 1 account at a time.

Right now I'm running 5x Shammies, all are 19th level. I tried running them through DM, had no problems at all leading up to the first boss, but I can't seem to get past him. I'm OOM super-fast and still need to work on my healing macros. I'm wondering if I should tough it out for a touch longer until I get the stackable Heal Totems, or if I'm likely to encounter issues as I progress with a lack of tanking.

To that end, I'm thinking about making a Pally, but not sure if the preferred spec is Prot or Ret. Anyone have any advice on that (or on the ogre boss in DM?)

Cheers,

Raddyghast=>Shaddyghast=>Raddoghast=>Shadoghast=>W yrnyghast

I was thinking that he'd still be fairly rugged as a ret spec with better DPS, having never played a tank before, it'd be a new mindset for me, not to mention a bit of a learning curve.

Thanks tons for the advice! :P