MMO game development

Hello guys. I have been using Photon Cloud for quite a while now and am very much satisfied with it. Now, we are planning to develop MMO game for that I researched and found Photon Server and Ulink. I would prefer Photon Server because of its pricing. I have done work only on client side so server side programming is new to me. I have few questions related to this:

1. Which one should I use? Photon Server or Ulink or any other and why?

2. Photon Server has MmoDemo example. Is this enough or would I have to extend it according to my requirements?

3. The Ulink example Snowbox has a server implementation as a Unity scene. Is it good enough?

Thanks in advance.