Wotlk was the game for me before Cata took off. I've been waiting for classic to reach Wotlk but this seems like a better alternative. Considering Im a pve, I assume Icecrown will be the server for me to join. Also, if there's any guides available like addons and general server things, I'll love to be pointed to them. And if there's a discord, even better.
Considering you're a PvE player, any realm will suit you (besides Blackrock).
Frostmourne is progressive realm and it moves through WotLK patches, so you might want to head there to experience whole WotLK. Keep in mind it's already on ToC stage.
Icecrown is your default Blizzard difficulty PvE.
Lordaeron is heavily PvE oriented with increased difficulty raids.
Also, if you'll have trouble with connecting to the game, FPS drops, settings reset (three most common issues here) make sure to do:
this (for connecting issues and settings reset): http://forum.warmane.com/showthread....07#post3129807
this (for FPS drops caused by mouse movement and memory crashes): disable hardware cursor setting in-game and download and apply this program to WoW.exe to allow it to use more RAM