I love architecture and am passionate about keeping the style of a house --- it drives me batty when I see changes to beautiful old houses that are totally out of character. So thank you for working to restore a cottage and protect its style!
If you simply google 'craftsman patio doors' you will find a lot of great examples, there are definitely a few specific styles that are true craftsman. Here are two links to get you started:
https://www.pinterest.com/pin/312929874081366508/
http://www.houzz.com/photos/60066311/Clear-9-Lite-...
And if you'd rather go slider, I'd stay in the same style... although I think french doors are much more attractive to buyers. But also depends on how much space you have for the doors to swing in (or out). And a single door is of course your possibility.
http://www.lowes.com/pd/JELD-WEN-W-2500-71-25-in-G...
If these styles are out of your budget, just do a single paned set of french doors (without the dividers in between, not classic craftsman).
That said, it also very much depends on the style of the windows and other doors in the house. If you want to post photos I"m happy to take a look and offer further advice.