How do I get "Threads / Posts" count to display like this?

[peugeot405]

try adding this in additional css:

.moderators, .subforums {
    background: none repeat scroll 0 0 #123456;
    border-radius: 5px 5px 5px 5px;
    clear: left;
    color: #FFFFFF;
    display: block;
    float: left;
    padding: 2px 4px;
    text-align: right;
}

don't forget to change the color codes to the color you want to use!