A popular memory chip used is SDINBDG4-8G from Sandisk, but we do not carry it. Some possible alternatives that we have in our system though are EM-108GBI-GRADE-ND, and 1982-1029-ND.
The main difference of 1982-1029-ND is that it has a supply voltage of 3.3v instead of a range from 2.7-3.7v.
The differences in EM-108GBI-GRADE-ND is that it has a lower clock speed of 52MHz instead of 200MHz that 1982-1029-ND has, and that is has a higher operating temperature of -40°C ~ 105°C instead of -40°C ~ 85°C that SDINBDG4-8G has.
Note at the time of this post that EM-10 8GB I-GRADE is a non-stocking option in our system.
Listing for EM-108GBI-GRADE-ND
Listing for 1982-1029-ND
Please review the datasheets to ensure the alternative will work for your application.