What git server solution to use on windows and active directory?

We are looking for the best solution for setting up a local git server. Our wishlist is

• run on Windows Server 2008R2
• small team - less than ten developers
• easy to set up
• easy to use
• active directory authentication of users
• robust
• web gui would be nice
• free would be nice

Solutions we're thinking about

• gitosis looks like a hassle to set up and has no web gui
• bare git on a windows file share - seems easy but no web gui of course
• gitstack looks good but is not free

Any advice?

I have made a great experience with Atlassian's Stash.

It costs 10$ for 10 Developers and supports Projects with multiple git repos.

You have nothing to setup since it comes with integrated git, ssh and http server. (Just the server itself duh - but its not that hard, 30 minutes should be enough)

It provides a nice Webgui. You should check it out, there is a test licence for 30 days I guess.