Probably, but I can't guarantee it. FastSPI is known not to compile under Arduino 1.0 yet, so if you're using the latest IDE, it could be an issue. You might also need to tweak the data rate for the current pixels (1 MHz). Otherwise, probably OK.
If in doubt, I'd suggest sticking with the stock WS2801 library
, or (if you'll be streaming data from a computer), the LEDstream sketch from Adalight
. Though neither contains 'fast' in the name, they actually perform just fine, and are known to work with the LEDs in the shop.