reach hkia at 1150pm midnight .

i need to go to guanzhao provicial bus station to take long distance bus to guilin. i had check thro internet that there is no coaches after mignight.the only way is to wait till morning. may i know what is the earlyst time from hkia? fare?duration?if the bus to guangzhao, is there a direct bus to provicial bus station? if no then where should i stop n how to go there... pls advice