Just looked through your website, great project!
However when you are investigating other blockchains beside ethereum, you should have a look at NEM.
There's already a similar project using the NEM blockchain, luxtag, which specializes in proof of ownership/authenticity.

The modum smart contracts are not restricted to a single blockchain. Our pilot projects, including those with a large Basel pharmaceutical company and a leading parcel distributor, used the Ethereum platform. Ethereum was chosen for its stability and its simplicity in creating the governing logic of the smart contract execution. However, modum.io remains agnostic in terms of blockchain use in order to avoid dependency on a single platform or limit the preferences of clientele. modum.io is currently testing the integration of other smart contract enabled blockchains.