It sounds like you're off to a great start with your marketplace idea! You've already mentioned some solid options like WordPress marketplace themes and no-code platforms like Bubble, both of which can be great depending on your budget and timeline. Another option worth considering could be white-label solutions—these can give you a head start with pre-built functionality that can be customized to suit your niche. If you’re thinking long-term scalability and want more control over the platform, then building from scratch (whether through hiring developers or a company) could offer greater flexibility. For a detailed look at the development process, here's an article that might provide some useful insights: https://www.cleveroad.com/blog/how-to-build-online-marketplace/. While it focuses on food ordering, the principles could easily apply to other marketplaces like yours.

Good luck with your project!