I have a new site covering the phonology and tones of Chinese dialects. I'm still adding data, but you can currently view tone data for more than 400 dialects eventually to be expanded to more than 1000 dialects. Languages included are 官話, 晉語, 淮南, 湘, 贛, 吳, 閩北, 閩南, 客家, 粵, and 平話, including some info on 越南 (Mandarin, Jin, Huainan, Xiang, Gan, Wu, Minbei, Minnan, Hakka, Cantonese, and Pinghua, including Vietnamese).
The main page is:
http://www.glossika.com/en/dict/lang.htm
James Campbell