I think the best you'll be able to do is the top 50 clients in the Organisation Summary Report report. Go:
Organisation/Summary Report
Make sure you are viewing the new version (link in top right hand corner).
Change the "SHOW TOP RESULTS" drop down box to 50. Go down to the clients section and update the number of clients to display.
Then in the top right hand corner on the on the "email" icon, which will let you schedule it to send you emailed reports of that page on a regular basis.