Looking for full stack dev for a marketing agency and SMB service build

I am looking for a dev expert/partner who can build a cloud based service that I have fully spec'd, I have many years of being the front-of-house marketing and product managing side of things in the SaaS world and need someone who can build to spec to deliver a complete engine for a unique blue-ocean marketing service aimed at SMBs, marketing agencies, and enterprises. It's actually a very small build in general and wouldn't require much reinventing of the wheel. If you having experience building a user login/control panel, forms, a simple database, linking to a pay portal, and APIs that other services can tap (this part is critical) you're 90% of the way there. I need it built using current mainstream software languages, databases, and tools. Experience creating a Github for 3rd party devs to interact with the service is a plus and a big plus is a general understanding of the SEO world (the more the better), so any experience doing dev work for an agency would be huge - you wont do any marketing but the service is aimed at people who do. This would be for equity and I would pick up launch expenses like hosting as long as we go to market on the cheap.