Morning,
are you asking about changing the bulb-system in your current halogen housings, or completely 'new' HID housings?
In any case, it might be cheaper/easier/more fun to find two OEM HID housings from a u-pick junkyard along with a highline CECM rather than aftermarket kits. I got the complete headlights here for 37$ CAD each, the Jetta GLI '09 highline CECM was 50$CAD. You'll also need 10-pin halogen to 12-pin HID headlight connectors (aliexpress has these) for that proper OEM look. You need to unpin/repin these, and run two trigger wires from pin 11 to the CECM for the shutter high beams (not critical though, as you can still run the normal halogen high beams instead)
Some jurisdictions may also require auto leveling HIDs, but I do not believe that this is required for the USA/Canada.
Get some quality bulbs while at it:
http://www.morimotohid.com/ (I'd recommend max 5000K)
Legalities vary on this kind of retrofit though... in the US it's pretty much illegal to do so. FMVSS 108 covers that.
But back to your question, yes they do exist (i.e.
https://www.xenonsonline.com/products/vw_golf_mk5_hid_kit)
