breakout boards plus - hard choice

As I come closer to retrofitting my B-port series I, in some ways the final choices of
electronics is becoming harder. Gecko 203V's stepper drivers appear to be a no-brainer, but
what stands between them and the PC is not so clear. For quite some time I was watching &
waiting on the G-Rex, but in its present evolution it seems too much - or too little - I'm not
quite sure. Then the PMDX motherboard looked interesting, but it doesn't support 203V's,
nor onboard spindle speed control. So the Sound Logic Combo board began to seem the
likely choice, when I came upon the Pico Universal Stepper Controller. This looks perhaps like
it has much of the G-rex functionality - especially encoder feedback - but minus the stand-
alone programability, which I don't believe I need.

Anybody willing to opine on the relative virtues of these boards?

BTW, I was assuming Mach3, until the UbuntuEMC came out, and now I'm not so sure on that
account either.

TIA

Steve clay-Young