When you say "spanking" are you referring to bare bottom, over the knee/domestic discipline type stuff?

That's not my thing so I can't point you in a specific direction. Gromet's Plaza and BDSM Library are continually publishing stuff but they seem often to be more severe BDSM stories featuring, heavy bondage, latex, slave training, captivity, various types pain play etc etc .....

Although, Gromet's seems to run the gambit from light and playful to full on fantasy such as various extreme activities in a NC or captive or kidnapped type scenario.