We are changing our system. We settled on git (but are open for alternatives) as long as we can selfhost it on our own machines.
Specs
Must have
- hosted on promise
 - reliabile
 - unlikely to be discontinued in the next >5 years
 - for a group of at least 20 people
 
Plus
- gui / windows integration
 


+1 for Gitlab. As the number of developers increases the features of Gitlab will get more and more important. Only OP can say, but if they’re closer to 9 developers than 2, I think it’s a safe bet they’ll need the extra features sooner rather than later.