Akai S1000 / S1100 samplers

Hi,

Just bougt a S1100 with 18 Mb RAMM.
it's got an internal harddrive with harddisk recording option but I still might update to 32 Mb 
nternal memory.

Is it true that AKAI memory chips are the same as Mac SIMMs?
And if so... which SIMMs should i get? (for which type Macintosh computer?)