I just recently purchased a Toshiba Satellite M40-JS8 notebook computer, and have been looking into upgrading the internal memory. I have read through the manual, and have found instructions on how this can be done. The manual, however says that only memory modules with the following part numbers can be used: PA3311U-1M25, PA3312U-1M51, and PA3313U-1M1G. My question is: do I need to use Toshiba speified parts with these model numbers, or can I just buy some RAM from this website (there's a store for this place near my house), and if so, which speed of RAM should I be buying? Thanks.