[Gustoo]

you can do /w all necro count

and I think /w all necro 40 60 count to see how many of those (pretty sure on this one)

Most guilds are happy to have a dedicated Cleric since a lot of people just have them for rez bots but not any really good players.

I would choose the class you think you will enjoy most. Necro is good for solo pharming not great for PVP. Shaman is great but everyone needs a ton of buffs from you. Ranger is fun but life will be rough, solo from 40+ for ranger super tough pre velious (panic animal) and is slow even with it.

If you don't grind up with a team you will probably find yourself alone a lot. Really though, if you choose a class you like nothing else will really matter. They are all great. Have fun.