… if anyone has or wants to create a spreadsheet, I’d be happy to include it in the list of artist checklists in the Artist Collector General Thread, if you’re kind enough to share it with the community 
As others have noted, I’ve also used a combination of serebii and bulbapedia for my own spreadsheets. But an Arita checklist is obviously a whole other level of workload than mine were.
Anyway, good luck with your awesome goal and sorry for the plug 