on the VF61 you have an audio support but not on the VF50. This is ok for me as I do not need audio. I am looking at a SODIMM solution that can just provide as many comms (3x SPI and 1 Ethernet) interfaces with as many GPIO as possible
See datasheet on link text
you can handle up to 103 GPIO and 16 analog input for COM (VF50)
it is mounted on Iris Board you can use only 26 GPIO and 4 analog input
You can also use our filters on our product website. Pretty much all our modules support 3 and more SPI channels. So you can just select the module of choice based on other factors such as performance, memory, price, etc. I hope this helps.