[Cdesja5]

Since the OP is not necessarily purchasing the books from Amazon and has epub books from his old Sony it makes more sense to continue in the same format... Epub is the #1 format for ebooks in Canada and unfortunately the kindle limits it's owner to reading Amazon format. Also the 3g version does not allow for all the features in Canada that are available in the US... The price here is another factor, it's almost double that of a Kobo Touch and more expensive than the Sony T1 which is considered "expensive" here.
I'm sure it's a fantastic ereader particularly if you live in the US but it does have its' limitations elsewhere.
From the Kindle Canada website:
While Kindle 3G Canada allows you to have wireless connection for free, only your connection to Amazon to download and purchase eBook is guaranteed. Some other services may come with additional cost such as personal file download and subscriptions. If you are located in an area where Amazon cannot maintain wireless connectivity, your use of Kindle may be limited when it comes to other services. Since your connection to Amazon is provided by third party wireless carriers, Amazon cannot guarantee that your Internet connection will remain the same. It will be greatly impacted by any circumstances that could result to modification or even loss of wireless connection. To learn more about Amazon’s scope of responsibility, check their Terms and Conditions here.