Best way to interface ADSP-SC584 with 2 LTC2344-18 ADCs

I am using ADSP-SC584 for a project. For the project I am interfacing 2 external ADCs and 2 external DACs with processor. I believe I can interface LTC2344-18 ADC to SC584 using SPORTs, or SPI or ACM. But since I am interfacing many external components, I don't want to use up too many pins.

What will be the best way to interface 2 LTC2344-18 ADCs to SC584 such that least number of serial communication pins gets consumed? Each ADC requires at least 4 serial outputs and 2 serial inputs ( 4 serial inputs, 2 serial output from SC584's perspective). For more information, here is the datasheet for LTC2344-18.