Hi,
just take the platform you're most comfortable with (Ruby on Rails, Sinatra, Node/Express, ASP.NET, whatever...) and implement your smallest possible product/service use cases (MVP-like) and ask your peers or future-customers to start working with it.
Then iterate though all the issues and suggestions to improve it.
First rule would be to get SOMETHING WORKING online asap.
You can go from there. When you're making money, start improving the product and the technology.
To address your needs you need to know what you need first. :)
Best regards,
Steviee