I'm mostly going to comment on the latter part of your question about vetting a developer for this project. As you mentioned you don't have the technical skill

I'm mostly going to comment on the latter part of your question about vetting a developer for this project. As you mentioned you don't have the technical skills to create this project yourself, it would be quite difficult to be able to vet someone more reliably than random chance. Obviously it would make sense for you to ask to see any related projects they've made, but I'd recommend having a technical friend help out with the vetting. Aside from past projects and their contribution to these projects, perhaps ask for a high level breakdown of how they would tackle this project. Have your technical friend to overlook this breakdown should weed out people who'd have little chance of delivering. Hopefully others can chime in here, good luck!