Can I found a small company on DevOps?
DevOps has three parts: Tooling/automation, Organizational, and Cultural.

You're basing your organizational structure and process' on your business' maturity.  Which is smart.  My experience in a startup and with a fortune 1000 company has afforded me the experience to denote that starting with DevOps is better for company growth.  It's efficient and fits nicely with agile.

Tooling

Being your maturity is really young, you should buy your DevOps process as saas products to reduce time to market.  Instead of Jenkins use circleCI or similar product.  Instead of VM's and docker, use Heroku.  Try and incorporate the toolset but do it in a manner that works for the size of your business.  If deploying code manually takes 4 hours a week and automating it in 1 hour saves that.  Do it.  

Organizational

Also from an organizational standpoint, you will naturally start with all developers as the responsible party for operations/features even product development.  Take a look at http://web.devopstopologies.com/  for organizational structures.  Our startup started with type 2, and as we mature will move toward type 7.  

Cultural

DevOps is simply teamwork.  Work together and everything gets easier.   It usually is a problem because leadership doesn't keep this in mind so as you start out, ensure that everyone is apart of the business.  This is also reflected in agile. 

So in short, yes pursue DevOps but do so at the level that meets your business maturity.