Version 1 or 2?
If you don’t need an original PCB, a Taito G-NET board is easier to find, cheaper, and will run both versions of G-Darius off cheap Compact Flash cards, as well as other great Taito shmups like RayStorm.
https://www.arcade-projects.com/threads/can-someone-school-me-on-taito-g-net-with-cf-cards.2622/
DM sentG-Net works too, but if you want the Version 2 PCB feel free to DM me.
thank you! untested thoughIn case you're still searching, there is a kit up for auction currently https://page.auctions.yahoo.co.jp/jp/auction/l1145510274