I'm working on a service called Protolaunch that does exactly that. You get help finding your ideal customers, a custom landing page optimized for conversions, and a digital marketing strategy to promote your brand and grow your email list of future customers. Getting market feedback and validation has always been the single best motivation to finish an MVP or business project for me personally and Protolaunch aims to make it a one step "pre-launch" process.

I'd love to get your thoughts and feedback!