Play what you want to play. Nothing is "needed" on this server as its a bunch of classic junkies all crammed into one tiny little Norrath.
With that said, a few things to keep in mind:
- Exp penalties exist
- Clerics are typical mainstays for groups
- Monks are likely the most prevalent class
- Casters are far less gear-dependent than their melee counterparts
- The opinion of the strict adherence to the "holy trinity" of war/clr/enc happens more often than I'd like to admit.