Phone systems (ACD)

Hi - We have an in-house call center and are looking to update our phone system. Does anyone use a system they find particularly good for ACD (automated call distribution)? Eventually, we'd love to find something that integrates with Tessitura (preferably not Shoretel), but any sort of recommendations or insights would be greatly appreciated.

Thank you!

Jessie Bagley
Director of Marketing and PR
Spoleto Festival USA