Brett's Salesletter Software is completely editable and so is able to be used for a range of products.
After using the software you'll have a salesletter that is based around an eBook. However the salesletter can then be edited to suit your needs, so you could then change all eBook references to whatever you need it to be.
The important thing is that the salesletter that is produced will contain all the essential components of a good salesletter. You're welcome to edit this as much as you need to before uploading it to your website or sending it to your potential customers.