Where to get FPGA cards for Jetson TX1

TX1s only came out few month, some members already started to test DMAs between FPGA cards and TX1s. Where can I get FPGA cards for connecting to PCIe of TX1?

Thanks in advance.

It appears many Xilinx FPGA cards with PCIe interface can be plugged in TX1 standard 4-lane PCIe connector (J2).