Need helps for long distance intercities bus. I plan to go to Zhangzhou for camp.

But before heading there, I'd like to see other china cities, the choice, neither Guangzhou or Beijing.

Since I haven't buy the flight ticket yet? May I have suggestions, which from these two cities that closest and have cheaper transport to the city? Can you give me details route and ticket fares for overnight bus or train to the city?
Thank you so much for your help