there are several servers on eqoa but for the past few years, the castle lightwolf server was and still is the only active server. as for what class, depends on what kind of class you like. there are 4 types of classes and they are tanks (warrior, shadowknight, and paladin), healers (shaman, druid, and cleric), casters (alchemist, enchanter, magician, necromancer, and wizard), and melee also known as damage dealers or dds (bard, monk, ranger, and rouge). go to
http://everquestonlineadventures.station.sony.com/ to help you understand eqoa a bit more