I posted a free page I wrote a while back for my site.  It lets you pull in the emails for customers who bought a particular SKU within a particular timeframe.  Then you can choose any email template to send them.  Works great when you have a recall notice or other advisory you need to send to shoppers who bought something within a certain timeframe.
You can find here in the AbleCommerce forums:  http://forums.ablecommerce.com/viewtopic.php?f=47&t=15301