Shield compatibility

Hello,

I purchased a SainSmart Arduino mega 2560 R3, and now I want to buy - an AdaFruit Wifi shield : http://www.adafruit.com/products/1491 -an AdaFruit NFC shield : http://www.adafruit.com/products/789

Are they compatible with my SainSmart ? If not, can you advise another shield ?

Thanks

Try asking on the Adafruit forum.