I'm not sure the Max 2 Mbps per channel matches with what you said of 1.25Msps (I,Q) data. Assuming the I,Q data is 8bit data that's 20Mbps / Channel or 160Mbps total for 8 Channels.
This is more than you're estimate of 2Mbps / Chan. (or 16Mbps total) but easily within the reach of EMIF16 which is > 100MB/s.
Best Regards,
Chad