None of those appear to be Arduino "shields", unless I'm not looking at them correctly? An Arduino shield is plug/play, whereas I would define a generic "module" as not.
And so is this: http://dx.com/p/arduino-compatible-gsm-gprs-shield-wireless-...
And this (includes an Arduino Uno compatible board for $80):http://dx.com/p/elecfreaks-diy-gprs-gsm-learning-development...