I'd want to develop it and test the products before promoting anything.

Try to request some samples, you get them at discounted price and is worth to have them to check the quality.

Shopstr is cool too, but I feel there's so much going on there that the products get lost and loose visibility really quickly.

We tested that too 😅 https://shopstr.store/npub13kkpytvjcxsqka9pdshw3094urgh8fxwx7ru258lved9wr7f35mspal584

Plebeian market is another good one
https://plebeian.market/p/d2b323fffd132e0fa76fbad5313b1547e47fe5b0233c2c8ff5ff4c0fe6009b17/stall/614bb48db263665a414cb9d0e3053ab6ab97316edb6685ed6e51c923160b97d8

Just keep an eye on shipping costs when using the nostr shops!