Sorry, for taking so long, I have been busy with my system etc. (not that you care
)
I bought them as a kit, together.
Bilstein sell the threaded body shocks, but I am sure they come as a kit with their specific springs.
But I know for a fact that Neupspeed and Bilstein will sell them individually, which will probably cost you about 300-400 a shock.
You have to call them though. I was investigating replacing my left rear shock when my sway bar pulled through the sub frame and the bar was digging into the shock.