I've added a very quick design document/block diagram to google drive here: 

https://docs.google.com/document/d/1JdDacofMxN9zo3MFpjHVc2o74f6vh41sJwJNfwpOXBM/edit?usp=sharing

The FPGA daughter card is FMC compatible although it uses the "exception" style in that the processing is happening on the daughter card, not on the motherboard as is the norm. The FPGA will be programmed by the ATSAM3x8E and should enable the full 140MSPS modulation the AD9914 is capable of. 

Currently a Spartan 6 LX16 is planned, although this may change to a Zynq depending on cost and flexibility.