No one can really tell you what to get, it's you that will have to live with it, but I think you need to do more research on gas vs aeg. You may be able to get away with gas only in toronto, but I wouldn't recommend it as a first and only gun, they can have more temperamental issues than an AEG.
1. Are you 18? if yes, then it's legal for you to buy/import. If no, then you are legally not allowed to buy from a store, online or otherwise in country or not. Otherwise the gun is perfectly fine to have as long as it meets output limitations required by the field or game organizer. Indoor 350fps outdoor 400fps with .2s.
2. ordering from the states is still not worth the risk, even with proper factory documentation and or modification that's properly documented, it's still up to the customs officer whether or not he wants to hold up your package. Every now and then you still hear of someone's package being held unreasonably long for inspection, or outright seized.2 Unless you are going to save significantly (don't forget to include taxes, shipping and brokerage into the US price) I still see no reason to buy something that's readily available in country. If you're saving a significant amount, is it really worth the gamble?
3. Cool down effect is not necessarily atmospheric/ambient temperature effect.
When it is actually cold outside the gas pressure is significantly less on propane, in closer to 0 temps the gun will eventually fail to completely cycle, if it fires at all. All green gas/propane guns will have this issue. It's the physics/chemistry of using propane.
Gas guns are still finicky beasts, I wouldn't call them reliable... they're more of a 2.5 season gun when they work. An AEG that's properly setup will be far more reliable as a 3.5/4 season gun in the GTA. Since outdoor games are going to be pretty rare in the winter anywhere in canada, but in UA now, you can technically play indoors all year round. The only problem is, gas or aeg, you're going to have an issue going from outdoor fps to indoor fps. 400 vs 350.
A gas gun with an npas can change fps reasonably easily, whereas an aeg requires disassembly and a spring swap. But gas is very finicky with ambient temperatures, so if you start the day at close to 20C and it goes up to 30C there is a huge fps swing, so your gun that might meet chrono at the beginning of the day will now be shooting too hard in the afternoon.