Well, I've talked to a fellow who lives in Canada about them. I'd assume the gun laws are similar. I'd go with an SKS semi-automatic rifle, in 'restricted' countries they're limited to fixed five round magazine with a steel plate welded into the magazine so it can only accept five rounds. The factory magazines accept 10 rounds, and you can buy extended magazines up to 20, 30, or 50 rounds, but I don't think they are available in Canada or Australia. I also believe the extended magazines are illegal in those countries, plus the UK. But you can still get one with a fixed five round magazine, and they're extremely fun to shoot with.
If you're looking for a handgun, I have a personal preference towards Smith and Wesson revolvers. I own a .357 model 586 and it's performed very reliably, and it's pretty accurate for a handgun. It can also chamber .38 special. The problem I have with .38 special, and even 9mm, is that they're not particularly hard hitting rounds. Usually it'll take several rounds to kill someone, and even if you don't want to kill them it'll take several rounds to knock them down to the point where you can either escape or call the police.
Do you at all have the option of getting a .45 caliber Colt semi-automatic or a Kimber .45 semi-automatic? If so, I would go with them. Really any .45 is a decent choice for self defense. The .45 ACP is a very reliable, hard hitting round that will put a person down in one or two shots. There's a reason it was called the "door buster" during WWII. For personal defense, I would say it's your best bet. Otherwise you can get a semi-automatic in 10mm magnum, also a very powerful round, I would say better than the .45 myself, as it's a magnum cartridge and firing at a higher velocity, as long as it's a fragmentation round it'll do the job and probably better. American Arms and Glock make 10mm models I know, and there's other companies out there. However 10mm ammunition isn't as common as .45, and thus more expensive. However I've fired both .45 ACP and 10mm, and honestly I'd say the 10mm is the better round.
If you're looking for a revolver, I would go with Smith & Wesson or Ruger. And I personally use a .357 Smith and Wesson Model 586 revolver with carved "dum dum" soft tip bullets for home defense. I've never had a loading or firing problem with my revolver. I have, however, fired enough pistols, in .22. 9mm, 7.62x25, .45, and even 10mm to come to the conclusion that semi-automatic handguns, especially when firing defensive ammunition and not full metal jacket ammunition, will fail to load. I don't trust them, your mileage may vary.
But for self defense, I really wouldn't go with anything less than a .357 magnum. A .38 special doesn't cut it, they don't have enough of a powder charge behind them to stop an attacker unless you shoot them directly in the face. It may happen, but it would be an off chance. So .357, .44, 10mm, .40 .45 ACP or .45 LC. Those would work, but 9mm, or .38 special, .22LR or .380 I would not recommend if you're looking at a handgun for self defense.
So yes, there's my two cents, coming from an American who has been around firearms since he was 10, and who has worked in a store that sold and refurbished firearms, and owns 10 firearms. And some people say I have an "unhealthy fixation" on firearms, and other people say I'm a "firearm genius". It's all a matter of perspective.