Hi grievous 7,
I have done some digging online but haven't found any information regarding who used the Saber design the Archon is based on (yet). I do remember there was a heated discussion on another forum as to where the design originally came from quite a few years ago. There was a single image everyone was trying to trace and the earliest picture they could find looked like this one but larger and had just the "Archon" on the white background. No names or info were attached to the picture.
This picture above came from a post asking if somebody could make a replica of it in Star Wars KOTOR. Another problem I had was the vast number of Lightsaber Modification Packs players had created of their designs and graphic artists creating 3d renders of sabers on sites like Deviantart and Pinterest.(There is one example by a guy called Lawson and he named his render Eindride Enigma)
If I do find more definitive info I will let you know, or maybe Brax or Phil could give you a better answer,
For Tyeth