From what i see so far, people that are working on fpga miners are wanting to keep it private for now which make sense. I did some small research, its viable to mine with today's fpgas you dont have to use top of the line fpga though, even mid range fpga's offer good options for mining.
Intel recently started to offer opencl sdk that can compile opencl code to Altera/Intel fpgas (not for all models) in my opinion this is a game changer you dont have to mess with tedious VHDL or Verilog code. If someone is more interested about this there is an article about it in this magazine
https://software.intel.com/en-us/download/parallel-universe-magazine-issue-31-january-2018Most of the manufacturers support openCL including Xilinx with SDaccel. I am just wanting to mess around with it. I managed to get the GOminer to work with Zcash on GPUs (although it was slow since I was using open source kernels), its was a great learning experience for someone as inexperienced as me.
I figure if I can get a starting point with a miner then I can trace it down and mess around with it as well. I am good at hacking others code but not a coder by nature.
I am using a Kintex 7 which has enough kick to do the mining imho but it will certainly not be fast.