Advice on FPGA pin choice for a kit.

Will you have at least one header for I/O?

I would recommend making a clock pin available from an external source. The dedicated clock pins are input-only. If you want to make the external pin useable as both a clock or a user I/O, then you could tie two pins together, i.e., route the signal from the header pin to both a dedicated clock input and to an I/O pin. This will increase the capacitance of the signal, but since you're running the signal to a header, you've already got an ugly transmission line, so its not really going to be that bad.

I mention this idea because of an issue I recently noticed. The Arrow BeMicro USB board does not route any clocks to its 80-pin expansion header, so you cannot use an external device that uses an external clock, eg., an ADC or DAC. The Arrow BeMicro-SDK does have clock pins on its edge connector. However, since those pins are input only, so they are not as 'general purpose' - I like the idea of routing a header signal to two pins to get the best of both worlds :)

How much do you think you kit will cost? Its pretty hard to beat the price of Terasic's DE0-nano ...

Cheers,

Dave