Good looking set with good looking kits! I dig it.
The spacebars kit is probably going to end up a bit on the expensive side, though. I think you could've forgone the small spacekeys in black (1.25c, 2c, 2.25c, 2.75c) without too much detriment to the buyer or the overall usefulness of the kit.
I also would've taken the opportunity to add either two 1.5u ◇ keys or a second 1.5u ☰ key to the icons kit, for Mac / OG HHKB bottom row users. Another approach would be to make the two 1.5u ☰ keys ◆ instead, for greater flexibility with legends.
But these are minor things. Overall, the set looks really good.