FreePBX on cloud

I am a new FreePBX user. I do not have much experience with VOIP. I just installed FreePBX 2.10 on RackSpace base on this instruction below:

1/I want to know how I can configure FreePBX on cloud? How incoming call from FreePBX forward through my office firewall to the SIP phone with a internal IP address and vice versa?
2/Between Amazon and Rackspace which one is better to have Free PBX install.
3/Which SIP phone provider is the best to go with?

  1. Your phones will need to “register” with your server to receive calls, you need to setup your office firewall to allow SIP and RTP traffic to and from the server, read the wiki . . .

  2. IMHO Neither.

  3. The one that suits your budget and meets your expectations, you will always have to balance off those two criteria, so be aware that any third party suggestions will always be biased by the suggestor’s purview.