I've trawled this topic and github but am still not sure what the best starting point for a new (Kintex7-325) fpga miner would be. 
Multicore is key and a pointer to a working open source software/fpga combo for a serial interface would be hugely appreciated but any sensible starting point would be fine - I expect to do some work!
I'm poking about with the verilog_xilinx port at the moment.