My (probable) 10 man team composistion

[Dusl]

> Yeah its so confusing and tough to decide.

Uh yeah. It's really, really hard.

If you want range dps, consider an elemental shaman. He has solid dps, very good utility, rezz, reincarnation and he doesn't need cloth as 4-6 toons of your current comp!
If your 2 priests are for healing, I would swap 1 priest for a holy pala or maybe resto druid.

I have no experience in endgame or 10 men boxing, but if you don't mind the additonal effort to build all the macros and stuff, mixed comps rocks in my theoretical opinion. You could even swap a guardian with a plate tank. Currently you wouldn't use any plate drops!