Multi User with Register, Avatar-Selecting Possibl.

I’m from Berlin and am a beginner in Unity.
we need to make a multi user real time environment, so that the users will be able to register and create account(PHP+MySQL) and login, then enter unity environment, select any 3D avatar and be able to walk arround and talk to each other (chat or Voice) and do some things…some thing typical like PS3 HOME, Counter Strike, WOW

i tried some tutorials… and here some quastions:

  • how should i beginn?!
  • should i use servers like SmartFox, NetDog and Photon (expensive charges!) ,Or is better to write my own server?!

i would be very happy about any tip, idea, tutorial…

smartfox pro / photon are actually minimal fees compared to what you are going to pay yourself / a programmer to develop something solid for you thats stable with hundreds or even thousands of users.

netdog on the other hand can become seriously expensive if the lowcost license is insufficient. Also you must own Unity pro and can only use it in standalone players as it relies on unmanaged dll / bundle.