When you say text size of 100k I assume you're talking about the size of the .img file. Please confirm.
During development phase it would be a good idea to have a larger size EEPROM (I would go with the max size and after the firmware is frozen will choose the EEPROM for production based on the size of final firmware) than required.
I checked the TEXT segment size in the result window of Eclipse. I think it is expensive to use the mega-bit class or multiple I2C EEPROM in terms of costs or footprint. Can I get the application note of using SPI EEPROM? (But, in another topic of this forum, I saw the problems of SPI-boot..)