Memory chips to expand the memory of the Satellit 700 are available from 2 manufacturers, Microchip & Xicor.
The chip designations are:
Microchip 24LC 16 B/P
Xicor X24 C16-P3
Note that these designations are exact. Both companies manufacture several versions of this memory chip, with different operating voltages and temperature tolerances. Those quoted above suit the Satellit 700 exactly. For information, the Satellit 700 provides an operating voltage of 3.3V within 10% to its memory chips.
Note also that the chips do not have to be installed in the set permanently to maintain their memory. You can obtain as many chips as you like, and remove/interchange them as required. The copy function is available so you can duplicate & exchange chips with other owners, and indeed, some years back, some clubs and radio based businesses, like Seibel-Verlag, sold pre-programmed chips.
The links below will take you to the websites of these 2 manufacturers, and on both of them you will find .PDF specification documents, and links to distributors and sales outlets to enable you to find the dealers nearest to you.