I was actually trying to convert this application to SD from SRAM/FLASH because I need more storage - about 130Mbytes.
I can easily achieve that level of capacity with RAM, but then I have to load the files onto it with serial data via the Arduino... which is SLLLLOOOOWWWW.
EDIT: I suppose I could move data to RAM from the SD card via SPI. I assume a sequential read would be faster...