Before you go offshore, especially to the Caribbeans, you should consider where you want to practice. If you are interested in a US residency, then the proposition is very complex. In fact three of my classmates from St George's in Grenada are Canadian and all three are stuck for VISAs. One signed outside of the match but is having visa problems nonetheless. One match at an Ivy League Internal Med program, but again, visa problems...he can't seem to get a J1 visa before starting in July. The third guy isn't graduating from SGU, so I'm not sure what's up with him. Either case, it's extremely easy to get into a Caribbean school. If you have something in the mid 20s MCAT and about a 3.0 GPA give or take a little bit, then you'll probably get into the "Harvard of the Caribbean"....but if your credentials are a lot higher, then you should definitely try AMCAS again.
There's quite a lot of loops to jump through as a foreign grad because you're answering to the ECFMG. There's extra tests, extra provisions. Also, top programs in most fields will pick over foreign grads. Competitive specialties rarely entertain IMG applications. In other words, being an IMG limits your choices for specialties. If you're interested in Internal med, then it probably won't matter to you. If you're interested in General Surgery, then you'll have to be amazing just to get a mid-tier residency. If you're interested in Neurosurgery, then you better reassess your credentials.
I'm not sure what the provision is for getting a Canadian residency from a foreign school, but it's probably not good.
Foreign schools such as the Caribbean money making machines are extremely expensive. As a Canadian citizen, you will not qualify for financial aid. If you are a US citizen, then depending on the Caribbean school you attend (only SGU and Ross qualifies for this), then you can get US Gov't Financial aid/loans. Plane tickets to the Caribbeans via Puerto Rico is expensive. Living in the Caribbeans is not cheap. Phone calls to the US runs about 1-3 bucks a MINUTE. Meats and fruits/vegetables are airshipped to the islands so they are very expensive. Tuition from SGU is about $35,000/year including your summer sessions. I'm not even going to talk about the customs tax at the Point Salines Airport in Grenada....if you have electronics/computers, just be sure to bring a few hundred dollars cash on-board to give to the customs officer.