http://www.puffin-press.com/ has a guide for GSL, NS and Newfoundland as well as Labrador. They are really good and depend on user updates. They also carry annual updates online between editions that are well worth downloading before you go. But they do not have enough chart insets to act as a paper back up by any means. Many of the older CHS paper charts are at a better scale than you can currently buy new. And indeed the rocks have not moved. But they had significant GPS datum issues, which is why CHS has been slow in some more remote parts to publish electronic charts. But they have been slowly getting this sorted out. I've cruised up there off and on since the late 70's. I inherited a full set of 1970's paper charts which is a huge sense of security to have along, and continue to pull them out for various reasons, including notes on charts re anchorages etc scribed by previous generation. Note that they changed the chart numbering system about 20 years ago so if you find old charts they may not relate to the current chart catalog numbers, but that does not mean they aren't still useful. You just need to find an old catalog to go with the old numbered charts. A good source of all things Canadian Maritimes is binnacle.com. This summer we did the circuit around Newfoundland. We worked off a mix of 10 year old CHS digital CD's - sold then by NDI, and I bought iNavX raster charts on ipad for areas where my NDI vintage were not covering. The east side of the Newfoundland Northern Peninsula for instance. Plus we still take the paper set for when the echarts crash at the critical moment. Best way to avoid that is to always have the relevant paper chart at the top of the pile.
Yup, that's one part of the world I'd never want to sail without the appropriate paper charts... My C-Maps for the plotter aren't bad, but they don't begin to compare to the beautiful CHS paper charts, some of the finest examples of cartographic art, IMHO. Particularly in regards to the topography of land masses, which is critical when cruising regions as mountainous as parts of Newfoundland and Labrador... The new series of CHS charts of Northern Labrador featuring the Torngat Mountains are simply beautiful to look at...
So far, I've found the charts of that region to be incredibly accurate, aside from the occasional datum offset issues... This is certainly not a place for the type of sailor becoming increasingly commonplace today - namely, the one who does not appreciate that your position as indicated on your plotter may not necessarily reflect your position on the Earth's surface :-)
The OP might want to keep an eye on the SSCA's Chart Exchange, but in my observation there are far more people looking for charts of Atlantic Canada, than offering them.... Any for sale always seem to go very quickly:
The Binnacle is a good source for new, and does offer free shipping for orders over $150, if memory serves... However, last time I looked, they actually showed a very limited offering of available charts for order on their site. No doubt they can get anything for you if requested, but it would seem to require a bit more work/communication with them to order what you want...
I ordered a large batch last year from Maryland Nautical, and was very pleased with their service. I found their site by far the most complete and easy to navigate, and with the very helpful feature of actually being able to see a picture of each chart depicted before ordering... Also, some of their smaller harbor charts are priced accordingly lower than the $19.80 for the standard CHS charts, something that Landfall Navigation or Bluewater does not necessarily appear to do...
As noted, the guides from the CCA/Puffin Press are a terrific resource, I wouldn't want to be without them... In addition, there is a superb guide for Newfoundland's Notre Dame Bay:
And here is an excellent online resource for Cape Breton and the Bras d'Or Lakes:
Finally, I'd try to obtain a copy of a terrific weather resource for Atlantic Canada... A most excellent reference, though be sure that the copy you're buying is in English, I believe they published one in French, as well: