Ren here from the Shopify support team.
This is a great question and such an excellent feature to add to your store to help increase sales.
There are a handful of options available to Canadian sellers:
Partial.ly gives customers the option to set-up a payment plan.
Paybright - gives the customer the option to apply for an instant loan and pay off over the course of a year. This can be set up directly in your Admin > Payment Providers > Alternative Providers.
Split Payments - is a little different and allows customers to split their payment among several cards or methods.
PUT IT ON LAY-BUY - Affordable payment plans.
What do you sell that you'll feel will benefit from adding one of these options to your store? Have you thought about marketing that fact that you'll be offering third-party financing?
Hope one of these options is what you're looking for. Let me know what you think.