I'd definitely go with back C. It's clean, intricate, and there's a much more balanced amount of negative space..
I love those courts! I'd just recommend checking your alignment on some. It's entirely possible that it's just me, but the crowns on the King of spades don't look centered.
In regards to the number cards, you should probably stick with the pips. Just filling in a dot for each higher card makes the number cards look too similar. If you wanted to keep that cool constellation design in the center, you could just remove the center pip and arrange the card's value in pips along the outer ring.
Another thing is the ace of spades. It's common for the AoS to be the most intricate card in the deck.
This deck has SO much potential to make a really cool ace!
One last thing: The pips for all the suits look very clean and even, except for the spade. Maybe try flipping the bottom triangle? As it it, it looks a bit too odd.
Great work so far! Can't wait to see the final version!