5 man Setup - Returning after several years away.

[Meeo]

Since we will still be rolling 5.4 for a bit til expansion, i'm curious to know peoples opinions on a pve setup i am looking into.

I possibly looking to roll the following:
Guardian Druid or Monk?
Warlock - Destruction
Hunter - Survival
Mage - Arcane (Edit: changed based on feedback)
Priest - Disc

I am very torn on the switching the paladin out for a druid instead, but i do not know enough about the current game to know which tank will fit me well. I will most likely level these up slowly and normally, without RAF (unless i start it next week after the new raf comes out).

My big question is does this group in the current environment provide enough dps/aoe dp, and is there any pros or cons against going druid over paladin. I will probably use the tank or the healer as my main for raiding eventually.

In my existing stockpile of classes i have i have my old classes for a year or so ago, at 85, Paladin, 3 Shamans, Priest, Druid, Warlock and an 80 Hunter. Would if be more wise to just stick with the existing group instead of going through the old content?

I know a lot of these questions are generally "play what you want" style of questions, but i really do not know what i want because i do not know the current game environment since i've been gone a long time.

Also i see a lot of people just rolling 3 members, is there a lot of content for 3 members, and is the gear comparable to what you could get as a 5 man team?

Thanks for the input and sorry for the long-windiness of the post.