That site seems pretty fishy.  Kingmax makes SDRAM rated at PC150, ie. 12.8% faster than PC133.  Kingmax is supposed to be quite good and you can read many threads discussing it at Anand's and many reviews of it online.  So why does PremierSystem advertise it as PC133 that is magically faster?  Note that in their photo of the module there is a sticker showing PC-133 while the link to Kingmax shows a photo clearly labelling the moduile PC-150.  Also, the Premier photo shows green PCB and the Kingmax site shows black PCB.  The Premier site says "This Synchronous Dynamic RAM (SDRAM) Double Inline Memory Module (DIMM) operates at 7 nanosconds, which is 25 percent faster than the industry standard 8ns mark."  Huh?  Since when is 8ns RAM the industry standard? And how is 7 25% less than 8?
Just buy some Crucial or Mushkin or Kingmax - from a reputable dealer.