I dont believe Crucial makes Rdram memory. If I were you my first choice would be Samsung. If they dont make the speed you need my next suggestions would either be Corsair or OCZ Technology. I'd pass on the kingston. Beware of memory sellers on pricewatch. Lots of those companies buy the chips and use their own pc boards. Lots of quality control problems. One of the most reliable and cheapest places on the net to buy computer parts is www.newegg.com
Crucial has top-notch service. I had a stick go bad after a couple of months, I called support, and they cross-shipped another stick. Had it the next day.
They are very helpful if you have any questions at all.