These people will give you a quote based on their database of patterns. They will not sell you the pattern... to my knowledge... and I can't think of any reason why a canvas maker would do that.
http://www.islandnauticalcanvas.com/
Your responsibility is to make any necessary measurements and alterations that you want to personalize the dodger, such as allowances for cockpit lines, hatch covers and their guides, etc. They may have pictures of your model that you can use for reference. All of this is included with price. Extra fees include window coverings and such. The quote for my Catalina 27 was $1700. Pretty good.. because more than one custom canvas shop here in San Diego quoted me over $4500. Yikes!!!.
Anyway... I chose not to go with them.... I can buy a commercial sewing machine and the
www.Sailrite.com dodger kit for less than $1500. Their kit shows you exactly how to build the pattern... and includes the pattern material plus the DVD instructional. The frame kit is part of the package and, imho, the key to the DIY method. Even though they sell really good sewing machines.... you can find heavy duty, canvas capable machines for sale in the $300-400 range.
Good luck.
