This is a list of patterns for regency clothing. Note that some of these are not particularly accurate (for the most accurate options, look to the scaled patterns) and that I cannot speak to the quality of the pattern or the ease of use for most of these. I have included sources, but I have not shopped at all of them myself.
Stores I have shopped at and can recommend are Patterns of Time and Wm. Booth, Draper.
If I have included a link to your work and you would like me to remove it, please let me know (just comment below). If you have any additions or revisions to offer, please also don’t hesistate to comment.
In the Long Run 
In books with Scaled patterns:
Dress design is by Talbot Hughes from the 1920’s
You can find it free online at google books
http://books.google.com/books?id=nnCBAAAAMAAJ&printsec=frontcover&dq=dress+design&hl=en&ei=7hsmTaiELpH0tgPYzZ2RAQ&sa=X&oi=book_result&ct=result&resnum=2&ved=0CDYQ6AEwAQ#v=onepage&q&f=false
Another book you will be interested in is Moden 1790-1840 ISBN 8717060494
which is were the Tidens Toj patterns are from
http://tidenstoej.natmus.dk/periode1/dragt.asp?ID=6
The last book I know that has patterns is Modesty to Mod from the Royal Ontario Museum 1967 which has a pattern for and 1823 dress
Thank you for this lovely list!
I have the Moden book and I love it! Sorry for not replying to comment for so long, but I appreciate the feedback.
I appreciate that you have links to multiple sources. The Sense & Sensibility patterns do not turn out well without major altering. Even wearing period correct underthings and fitting it to your size, I still had to take almost 12″ of fabric out of the waist of my spencer jacket. The Country Wives patterns are okay but the directions are often confusing.
Thank you for your feedback! Much appreciated!