If you are a not a programmer, then there is only one way for you to get bitstreams, is to contact someone from the forum who have already worked with FPGA and ask from them which they won't sell for free.
FPGA(s) have ridiculous high hashrate with very low power consumptions but requires a great deal of programming knowledge to get them to work, not even easily accessible to purchase.
A thread that I follow regarding FPGA:
https://bitcointalk.org/index.php?topic=3459858.0Contact Whitefire990, he may be able to assist you.