As VeeTpl suggests, there's a good number of high quality RP servers out there, often with various additions to the game that weren't available in the original trio of Neverwinter Nights Diamond. You'll hear about something called the CEP (Community Expansion Pack) that added tons of new clothes, monsters, etc. Servers can also create their own classes and such using things called "hak packs".
I play on a server called The Way Inn (
http://www.thewayinn.net), for example, where the maximum level is capped at 20, whereas Amia, unless I'm mistaken, is capped at 30. The Way Inn's world has been designed with, at least in my mind, a Baldur's Gate, Pen and Paper kind of feel, where leveling is slower and feels more important, and I've been there over a year and a half now.
If you go the RP route, it's important to find a setting that fits your goals and what you're looking for from an RP server, but believe me, there are several good servers out there.