Yes, but the problem is that they use their own gentoo based environment that they update as time go... To do anything custom that they didn't plan beforehand,

Yes, but the problem is that they use their own gentoo based environment that they update as time go... To do anything custom that they didn't plan beforehand, you need to create custom chef recipes that will be executed whenever a new instance is provisioned or if you deploy with their web interface (but not if you deploy with capistrano). The problem is that it's hard to make sure that the custom chef recipes will work when the underlying environment changes and you are not told ahead of time of those changes...