Which services of Photon are the best for me?

Hi everyone

A thing that I'd like to develop is inviting users to my lobby in real-time. So I though that Chat Server was the best solution and then I found out Photon Chat. However, the more I research Photon services, the more I'm confused about which service is the best for me because I need Chat Server to invite users and I need LoadBalancing but I don't know where Photon Chat is scalable or not.

Any help is appreciated.