It would be easy to alter the link-click counter scripts you've found. If you know how to use MySQL, you should be able to construct a table that will be able to record this information for all users.
Here's an example of a query that would make a good table:
CREATE TABLE linkclicks (ammount INT, user TEXT, time TEXT)
"time" would only be TEXT if you were using date(). If you plan on using a UNIX timestamp, it'd be INT.
Now, everytime the link is counted, have it update the ammount:
$result = mysql_query("SELECT * FROM linkclicks") or die("Error querying database.");
while ($line = mysql_fetch_array($result, MYSQL_NUM)) {
$ammount = $line[0];
}
$ammount += 1;
Then run this query to update it:
UPDATE linkclicks SET ammount=$ammount WHERE user="$username"