You are right about the pinouts being all different, nothing generic about that. I2C has more initial setup time then SPI, once you get your routines/macros down, then no big deal either way.
Looks like Microchip has an SPI eeprom, so a 25LC256, Maxim has clones in SPI too, but they're kind of spendy. Maxim is pretty good with their samples, but will opt for a Seiko S-35190A-J8T1G (RTC), and a plain vanilla temp sensor LM74CIM-5.
The digital pot and DAC sound good, but will wait till a particular project comes to mind. Perhaps a TLC5945 led driver, but that's not exactly SPI.