Hello all, I'm hoping that someone could help me out with some beginner's questions.

I have a Giant Anyroad 1 which has disc brakes. I'm interested in buying a better set of wheels that I can quickly put on for group rides and tri races and keep the stock set for more leisurely rides. But what exactly would I need to buy in order to have two sets that can easily and quickly be swapped?

Wheels, inner tubes and tyres obviously.

Hubs - Do they usually come with the wheels?

Disc brakes - would they come with the wheels? Is it easy to make sure a new set would fit into the existing brakes?

Rear gear cassette - should I buy a second one or is it possible to swap my existing one over?

And finally, do you think it is worth it? With the stock wheels I can average 30kmph over 50k or so. Would there be a clear different on better wheels?

Many thanks
Duraz