I built the environment on asterisk from source. I needed the database replication and failover capabilities. Honestly, I’m sure there are quite a few people here who could build a system, but I suspect most will be hesitant. I spent the better part of 10 months building this system and 4 web interfaces. I didn’t get much direction until I was mostly done. Luckily, I had experience building our other systems and a telecom guy who was familiar with common features, and some uncommon. Yet, I still get new feature requests. “Can you make the lunch-time queue closed message automatically be different than the after hours or no agents closed message?” That one came in on Friday.
There are a few things developers don’t like to tolerate; ongoing maintenance, constant modification and feature requests, and scope creep. You’ll need to define the specifics of your request before anyone would likely offer to help build it. In just a couple hours, most anyone here could build a system from scratch and have it making calls between endpoints, but if you ask for IVRs, Queues, Parking, Paging, blacklisting, forwarding, pickup groups, call recording, reporting, findme/followme, conference bridges, ring groups, phone provisioning, voicemail, etc. you’d be asking for quite a lot of time to be invested. Also, if you’re looking for 99.999% uptime, you’ll be adding time for clustering and network upgrades.
People do this out of necessity and/or the love of open source and Asterisk. I don’t think I can share the system I assembled because my hospital paid me to build most of it, but perhaps someone else here has a pre-built system they would be willing to share or sell.