Practice Management Systems

I am looking to upgrade our practice management system as the current system is not good enough for modern practices. I am looking for a large system for approx 100 users that ideally has the following:

1. Time and fees.

2. Job and staff scheduling, and tracking.

3. Document management - I see this as an opportunity to go paperless. This should include email communication management as well.

4. Contact management -  the ability to view a client/contact with all associated documents and communication (l guess this is linked to document management).

5. Possibly personal tax. This is not vital but I would be interested in upgrading our current personal tax system if the new system has a better personal tax tax module.

All of the above should be running in a single integrated database rather than separate loosely linked modules.

I am not looking to upgrade our audit, accounts production and corporation tax system.

I would appreciate any recommendations from users of systems with similar functionality.

Thanks