If you don't mind hard coding, add a logic to webapps\chat-portlet\view.jsp in the for loop to show only your selected users.
<%
for (Object[] buddy : buddies) {
long userId = (Long)buddy[0];
String firstName = (String)buddy[1];
String middleName = (String)buddy[2];
String lastName = (String)buddy[3];
long portraitId = (Long)buddy[4];
boolean awake = (Boolean)buddy[5];
String fullName = ContactConstants.getFullName(firstName, middleName, lastName); <- add if block using fullName to skip display
%>
