Database with PIC
(from the other post)
mmmm, you can't access both SPI and I2C from the same pins at the same time! you can search for a PIC controller with two MSSP (one will be for the memory, and the other for the SD) (18f46j50)
other thing is to implement software I2C, but it's not as fast, but at least, you can reach the 100kHz. this could be your best option right now...
and lastly, you can try searching for a SPI memory somthing like the 23k256 or something SPI so you can sare MOSI and MISO (SDI and SDO) but connect a different CS for both SD an RAM...