In no mean do I intend for this post to sound harsh or critical nor am I insulting you as a handler or whatever, I'm just giving you my straight up opinion based on the very few facts I know about you and your interests.
Tollers are plenty driven and have heaps of energy.
If you've never had a sport dog before and never dabbled in sports I really don't suggest you go with either a border collie or a toller just so you can have the best agility/sport dog around. Besides, if you wanted extreme utility these days it's the borderjacks that are popping up.
Since you're giving yourself 5 years I'd take out the dogs you have now, whether they're driven or not, and sign up for agility classes. Most dogs will at the very least learn agility given the right class method. Go to at least six and see if it's something you're actually going to really commit to. I, personally, have seen many people who become enraptured with the idea of a sport dog and becoming the best, then getting the super drivey working breed like the border collie, malinois, toller, etc mostly in the name of sport, then realizing a. the dog is too much or b. they aren't as into the sport as they thought or don't have the time to dedicate and now fido, who is still very loved, is getting the short end of the stick because they aren't doing what's in their blood and getting the stimulation they were bought for.
True driven winning machine dogs need to be taken out and practiced with on a regular basis. BCs in particular need hours and hours of exercise. Working with a family member's dog from time to time is one thing, having your own is another.
It's like when people say they want a Malinois because its work ethic is solid and they're like german shepherds on crack and then having a big bucket of uneven nerves, unwanted aggression, and a dog that has too much energy to stay still for 30 seconds.
I say this because 3 years ago I was obsessed with the idea of a competition border collie or a toller as well. I was all about the "omg I love the energy and work appeal and I want to win and I want a dog that can do it all". I'm glad fate didn't give me a border collie with that attitude like I so badly wanted. Because I, now in retrospect, was not ready for that even though I grew up with German Shepherds and worked in kennels and had lots of experience with dogs and training. Instead I got Baby and dabbled in agility, I like it but I don't think I'll ever be traveling America for it. It's a sport me and my dogs have fun with, we rule it, it doesn't rule us.
I'm not saying you'll be like me, I'm just saying it's something to seriously consider. I honestly think unless you've been competing with dogs before or have dogs you work every day in some form of competition venue then you really shouldn't be getting the crack of the doggy sport world.
I think the most successful stories anyway are to start slow and work your way into a run. Find a driven dog that isn't going to bounce of the walls. Once you've master agility and gotten far into the agility world with that dog graduate yourself in life to get another dog (keeping your other of course) by getting the "best" of the sport.
If you're still set on a driven dog why not get one that's a bit older from a rescue? They'll let you know if the drive is there but the off switch is clearly defined. Heck, I've even seen on more than one occasion some slightly older dogs (4 or 5 which still have plenty of vigor in most working breeds) that already know agility and are proven to like it.
I'd say for your first agility dog, go with a rescue.
Most rescues (especially breed specific) will be able to give you a basic profile of the dog. If you speak with a Border Collie or Toller rescue, they will likely direct you to those dogs that are more likely to excel at agility.
I'd go with an older, more established one if possible as they can be a little more compliant and easier to work with. Not to mention, have lower exercise needs which can be a bonus for a first time agility star handler. By the way, there are a lot of all time agility winners that were rescues
Who knows? It may be YOU that doesn't enjoy agility or even if you get a dog as a puppy, maybe the dog just doesn't enjoy agility. I know someone that got a pup, raised it to be a sport dog and even though it's super high energy and likes learning the dog just doesn't have fun running courses; it much more enjoys herding which is not the handlers first choice of sport but goes with it anyway lol.
But I do love the Toller fur.
my parents don't think 3 dogs and 3 parrots in the same house will be a good idea. Do you have a favourite breed yet?? I love the Pyrenean Shepherd!! But they're not registered in Australia yet 
Haha, I'm just kidding. I'm a bit jealous you live in Australia. If I lived there, I would so get a Kelpie dog!
