Our Cairnsmore1 is still available as a grade-B. Don't be put off by the grade-B as most of these are 760-840MH/s running a Glasswalker build. It's here http://www.enterpoint.co.uk/shop/en/107-cairnsmore-1-grade-b.html. I will say that we won't ship anything now until 3rd January as we are effectively shut down now for Christmas and New Year.

If you just want to tinker with FPGAs most bitcoin mining boards are not very good boards to learn FPGA design and programming. Many use XC6SLX150 FPGAs and these need a full expensive toolset to build a design. If you want to do some basic learning have a look at boards like our Polmaddie range which are aimed at teaching and learning and basically fairly cheap and simple to use.