This thread may be of interest for finding lie-flats on domestic routes other than SFO/LAX-JFK:
Domestic Wide-Body Opportunities: The Definitive Thread
The wiki there lists a technique for searching for specific aircraft flying hub-to-hub, which works for the A330 and 747; unfortunately it cannot be used to distinguish between the 767 with 1-2-1 lie-flats and the domestic 767 with the widely reviled 2-2-2 F cabin.
Also
Dedicated Flat Bed Routes and domestic lie-flat / flat bed route but this thread gets far less traffic. The ITA aircraft designator also fails to distinguish between 757 variants, unfortunately.