Help with Tag Cloud

I am trying to build a stylized tag cloud that looks like this mock-up: https://www.athleteswhotweet.com/tagwidget.png

I have managed to find this code:

<?php wp_tag_cloud('smallest=8&largest=8&number=10&orderby=count&order=DESC'); ?>

I think I also need to incorporate the topic_count_text_callback function to show the count in the black box right?

How would I do this from a PHP and HTML perspective?

Something like:

<ul class="team">
<li><?php wp_tag_cloud('smallest=8&largest=8&number=10&orderby=count&order=DESC'); ?><span><?php wp_tag_cloud('topic_count_text_callback=default_topic_count_text'); ?></span></li>
</ul>

I know that’s not valid, but basically what I need is the count to appear between the <span>’s as they format the count box.

Can someone please help?

Thanks,

Jon