FusionPBX:Community portal

Hi, I installled FusionPBX on Debian Wheezy. It all went OK, all the compiling and everything. So now I have a working com-server on a public IP-address. The next thing I want is a soft phone on my website, for my members/users to talk to each other, only by voice. I am not interested in connections with public PSTN's, so the commercial providers don't interest me. What is the best choice for a soft (SIP) phone I can configure? Thanks for your contribution.