Be very careful with ChicagoVPS. A lot of people just lost a bunch of VPS' because their master password was hacked, and the hacker deleted many of the VMs. Some were lucky.
For $15/month, you can get a PBX-In-A-Flash virtual from RentPBX.com. I'm a customer and very, very happy. One minute after ordering your PBX will be up and running, with the latest PIAF build.
That said, I also have PIAF running on a RasPi and a Dual-Core-Atom-based system.
If you are going to have your own pbx on site, where is the application?
- If it is at home, do you have teenagers playing games or doing bittorrent? Bandwidth may be an issue.
- If you are in a business, how much internet bandwidth do you have? Can you run a seperate network/internet connection for the PBX. It may not be an issue, but you may want a router you can set up QOS on.
What I do is trunk my RasPi in the house to my main PBX on RentPBX.
(It's a SOHO consulting biz).
All three -- host, RasPi or Atom -- are great low-cost solutions.--
VoIP Geek/Customer of voip.ms, vitelity, flowroute, callcentric, localphone, didforsale, voicemeup among others/Asterisk-PIAF user/FreeSwitch app developer/Consulting