Henry needs a PBX system. Leo recommends Ring Central. It's powerful, all online, and can handle dozens of employees with individual phones or routing to cellphones. Leo says he gets very good results. He'll just have to have sufficient internet to handle it.
What phones should he get? Leo says that PolyComs are great and they have a deal right now, but one get one free for up to 20 phones.
Check out Henry's Costume Site at What You Want Productions.
(Disclaimer: RingCentral is an advertiser).