Daniel,
The USER Table the is part of the RT DataBase has a lot of info that
may correlate to your client info needs. Why not just use that? As to
project billing rate/project info, you're right, a Custom Field would
work well AND there are some extension available that will highlight
G'day.
A client of mine has been using a product to do task, project, client
and billing management, AllocPSA. For various reasons they are
considering moving away from that to something more open and widely used
and supported.
My recommendation, for task tracking, is Request Tracker: I have
