I'm going to ask my mother because I absolutely love this music too! I heard Teresa Teng has done some enka-style recordings in Taiwanese (technically she's Chinese, I believe, but whatever, it's all good).

Your best bet might actually be to go into some Taiwanese book stores in the US. World Journal (the Taiwanese daily newspaper)actually has a few branches of their own bookstore scattered across the US - I would run a google search (like World Journal Bookstore -insert name of your hometown here-) and stop by the bookstore or call them to find out.

If I discover anything after speaking to my mother I'll let you know. I have a feeling she's just going to suggest I call up my obasan and ask her to mail me CD's though :D

Good luck and let me know if you find anything too!

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.