Have you tried polishing down the original assemblies? You can sand & polish them then re-coat them in clearcoat to restore their appearance. You can run a little bead of sealant around them too.
The halogen assemblies are much cheaper, and look exactly the same. They just don't have the ballasts and the self leveling motors.
They look the same, but they aren't the same. In order to convert from HID to Halogen and then back to HID with a retrofit kit you need to shell out $400 each for the halogen assemblies, then purchase a retrofit kit, never mind the fact that your harness is for HID, do you have to convert that back? This would still run you $1,000 easy, and you loose the projectors that are optimized for HID, and the auto-leveling which is a safety feature IMHO. In short...you will reduce the effectiveness of your headlights.
I think the solution is to try and restore the lights you've got.