Hi,
Just joined this forum, so I don't know if you've found something in the meantime. Anyhow, I use act28.CRM (http://crm.act28.com) primarily for time billing and invoicing. It also has all the other features you listed - project management, file management, calendars, todo lists, and accounting. The project management module has issues tracking (which you could use as a bug tracker).
HTH