From Key West to the topmost Northwest Passages Islands is about 4,000 miles which is a theoretical minimum of 20 milliseconds. Your theoretical minimum roundtrip time is 40 ms. I think you can safely remove the boundaries of physics from the equation. If you're in Toronto, then most of your customers will be much closer to you.
What you need to accomplish this is a reliable network carrier. Ask for information concerning things like:
- Latency. What kind of response times are provided from the different carriers in your area. Can you get a blended line that chooses the best path?
- Bandwidth or "Committed information rate". What is the minimum amount of "space" on the wire that is available at any given time? What is the maximum amount data that can be sent over the wire at standard rates?
- Burst rate. What numbers do they provide for bursting and how do they charge for bursts?
Fortunately, physics is smiling on you and you have nothing to worry about from that standpoint. You do, however, have to worry about network carriers and their numbers and "special math". But that's exactly what you should be worrying about right now anyway.
So in effect, not much changes, except maybe your awareness of what should be considered. =)
In light of your edit, I'm not sure what you mean by
setting up my own server in Canada versus a dedicated server in the US. Would you be getting a dedicated in Canada or standing up your own? IMO, you should get a dedicated server hosted by someone else for a monthly fee. It's too much hassle to manage and be liable for your own hardware for just one box.
So, a dedicated box in the US should be virtually the same price in Canada, and at that rate you'd likely not get visitation rights to the colocation rack no matter how close you were to it. Might as well get it somewhere in America, IMO. Chicago and Dallas would be two good spots for connectivity and range of selection.