The spider eye lamp is from a Nissan Cima/Infiniti Q45.
I'm more a fan of projector lamps than HID. I haven't seen much for 5 3/4 inch quad lamps. It would be nice to come up with a chrome surround and clear lens to house a Hella 90mm so it would blend with 60's and 70's styling as well as the Rocky Auto lamp does.
There have been a few people that have modified BMW headlamps from I think late 80's early 90's 3 series to fit into the quad lamp setups.
As for blitzk08 it is pretty much a plug and play setup, the H4 conversion is out there. Hella makes a Eurovision bucket iirc that is "not DOT approved" but is excellent for this setup and I know quite a few people that so use it and not have any issues. The HID setup is one that just drops in and plugs into the harness and the ballast gets placed in a place that has good airflow to keep them cool
Or does he need help jiggling it?