So you want it below the IM, MSC, etc icons? (I thought your arrow was just showing the image blown up).
HTML Code:
$template_hook[postbit_userinfo_right]
<div>$post[icqicon] $post[aimicon] $post[msnicon] $post[yahooicon] $post[skypeicon]</div>
<div><a href="http://link.to.paypal/"><img src="paypal.jpg"></a></div>
</div>
</td>
If you need more space, add a break - <br />