I set up an Elastix PBX with a VoicePulse.com SIP trunk. Elastix is Asterisk and free. The GUI looks pretty good and I was able to get everything set up in a couple of hours. I have never set up a PBX in my life.
VoicePulse.com is - inappropriate. They seem to be highly US centric (according to their plans and site) and I want to call from the Near East to Europe, mostly. So - not for me I guess.