Can i book a return bus ticket on my name to guangzhou china from hongkong? I want to buy it now.

i am planning to visit china, but i am now in canada. i will go to HK to see my girlfriend. then from there i want to go to Guangzhou, but the visa authority want a return ticket in my name right now when i apply for the visa. can i buy in canadian dollars a bus ticket now that i can present to the visa people here in Canada?