Actually Teresa Teng was Taiwanese, though she was quite popular in China as well. She recorded mainly in Mandarin, and fairly often in Japanese (including some enka), but she did do some recordings in Hoklo (Taiwanese). Still, if you want singers who specialized in enka-style Hoklo songs, I'd suggest singers like Hong Yifeng (洪一峰), Wen Hsia (文夏), Chen Fenlan (陳芬蘭), Ji Luhsia (紀露霞) and Wu Jinhuai (吳晉淮), to name a few of the most popular. In Taiwan, CDs by these singers are easy to find, and you can also find them in Malaysia and Singapore. However, I'm not sure where you could get them outside of Asia. Perhaps you can find a seller on eBay or a site like that who'd be willing to ship CDs overseas.