Thanks for your reply.

As my boyfriend and I have never lived together, we thought a trial period would be a better idea than diving in headfirst to marriage. Our resulting options were either a Visitor visa or a Study Permit, from what I could determine...
From what I have read, a Visitor visa would be more difficult for my boyfriend to obtain than the Study Permit... and the Study Permit has the added benefit of possible extensions.
We also decided on the Study Permit route because two of my Colombian brother-in-law's cousins have come to study English in Canada for six months in the past, one arrived last January and returned to Colombia last summer.
They were both in their early 20s with no property in their names in Colombia, just family... so their ties were pretty much the same as my boyfriend's are. What's more, he should be able to get a letter from his job to state they will hire him back once he has finished his English studies here...
When we apply for the Study Permit, we plan to include a receipt for four months of English courses at Hansa Language Centre in Toronto, and a balance in his bank account that will cover six months of living expenses (I read that you need $833/month) and coverage for return airfare.
The only thing I am still unsure of is his medical insurance... is it best to get that through his school or privately?
Any further informed thoughts on our situation would be greatly appreciated!