http://wiki.project1999.com/Character_Races
Rarest class is rangers by far. Then prolly necro, then mage. After that maybe enchanter and tanks, especially hybrids.
Ranger is a decent all around class at 60. Not much burst dps, but some healing and great buffs. Will be pretty great in pvp in velious with a good bow.
Necro is going to be a great class for pvp once resists are fixed, as life taps and dots of mostly unresistable. Also good for solo or group pve. Not so amazing for raiding but always useful if you dont mind spending 90% of your time casting dmf and pumping mana to other buffers/healers.
End the end, play what you like and plan for the long term. If you only plan on playing casually, casters are best. If you like to raid and group, tank/clr/melee dps will be best.