Javascript
A quick note: your spreadsheet had better support arbitrary-precision currency math, if it doesn't already. That's table stakes for a spreadsheet.
To answer your real question, I'd suggest doubling down on the sqlite side and taking things in a relational direction. Spreadsheets are good at tracking 1:1 or 1:many relationships, but my spreadsheets inevitably grow in a many:many direction and I find myself wishing for queries and junction tables.