If I were to do a pure Pve group again with 1 tank 1 healer and 3 dps I whould go with:
Pala tank: great on aoe, needs not much attention
Shaman healer: resto shams are highly underrated in 5man situations in my opinion. They have decent/good single target heals, they can pee heal if the group takes some damage (imho the priests group heal usually does too much, chain heal is usually okay). They have excellent utilities via totems. If yopu have a mob which fears or uses poison just drop the appropriate totem and forget about it - no active action necessary is always good. Heroism rocks
3 fire mages: great damage, intbuff etc. A case can be made for adding an elesham, lock or shadowpriest but I whould prefere the extra Aoe power.
Although this is just a suggestion I highly recomend pala tank and sham healer.
Bunny