The bitstream format isn't anything special. It's whatever Xilinx says it is for the Spartan 6. Any bitfile generated by ISE for the XC6SLX16 could be uploaded via the (generic) Cypress FX2LP chip.
This is all relatively old hardware, very well-documented and well-understood but still quite capable. It has a lot in common with the earlier-generation Ettus USRP receivers that used the FX2.
A lot more, actually. Manufacturer's specs for the ISL98002CRZ-170  say it'll do 170 MSPS, with an analog bandwidth of 780 MHz. It's actually a rather impressive ADC! The question would be whether it can be convinced to sample continuously.
I wasn't aware of that. This is even better of course!