Gyuanying is a really nice spot, but not much out there in term of accomodation.
If you are willing to travel a bit further, Zhunan is a nice place (also called Chunan or Jhunan). There is a nice surf club called "the spot" where you can have basic accomodation. There are always a few riders on weekend there. Here is the link the the website: http://www.spot.com.tw
Tony, the owner, is a really nice guy and you can contact him for more info.
I would definitely recommend a wetsuit at this time of the year.
Have a good one,