Hi Doorknob !
We have a picture of a -C model with the connectors it comes with on the kickstarter page :
Attachment 202588
It includes everything on that picture ( that's the 5XC version, 4XC and 3XC have the same, with the connectors they don't need removed ).
About upgrading, you'd have to add the IC ( A4982 ), and about a dozen passives.*It can be done, but if you think you'll upgrade someday I'd recommend going with a 4X*or a 5X*directly. It can be fun if you enjoy SMT soldering though, nothing difficult.
Thanks for pointing out the shapeoko forums, I'll post there !
Cheers !