Normaly when Enterprise customers want to make changes to drop the old PBX and use Lync as the phone system, they do need third party addons for Lync.
EVRY where I work can do this for you. We have created a Enterprise package for 100 users and more.
This will be like this:
HP 16 blade servers
Lync Enterprise Edition
Teleopti CCC Workforce Management
Hardware Load balancing from BigIP
As a client you can either lease this and pay a monthly fee or you can buy it from us. All will be installed in the cost for the package.
Take contact if you want more information