I think the best way from Hongkong to Guangzhou is taking a train from Kowloon. It costs about CNY83 for a hard sleeper. Furthurmore, Baima Clothing City is near to Guangzhou East railway station where the train from Hk to Guangzhou arrives. Summer clothes are available in mid March, but the summer clothes sold then are either new-style at high prices or old-style ones of the past year. There are economical hotels near Guangzhou East Railway stations like Home Inn (Zhujiang New Town), Guangzhou, Guangzhou Can Beyond Business Hotel or Home Inn (Shengdi Square), Guangzhou. In order to smooth your travel, I think you should book a hotel in advance.