Sorry I might have understood your question in correctly.
Would you like to show the customized chat in a popup window?
Something like this:
window.open('yourpage.htm','pagename','resizable,height=600,width=370'); return false;
If you would like to open the iframe on your site itself, then yes you could use one of the plugins to create the popup containing an iframe.
This popup contains an iframe using Popup Maker.