I wish we could order just a set of keycaps without the ergodox. I already have an ergodox with DSA but would love to try DCS. I even wouldn't mind ordering another ergodox with TWO sets of keycaps for this purpose.
ClarkBattleIf you wouldn't mind spending more cash (and time) you can manually buy their individual blank pack.
What you need for an ErgoDox is 60pcs 1u, 12pcs 1.5u, and 4pcs 2u keys. I believe PMK sells the 1u in a pack of 10 and 1.5u 2u in a pack of 4.
As we talk about DCS you need to mind the row profile too, most of DCS keyboards go with R4-R4-R3-R2-R1-R1 from the most top (F keys) to the bottom (Ctrl Alt). I can't help you much for the row arrangement in DCS ErgoDox since I never put my hand on them.
This what I mean individual blank pack:
http://pimpmykeyboard.com/blank-key-packs/dcs/