If all you care about is that there is a working store which comes with the distro, then you want Canary.
If you are in fact keen to only use a more close to TFS, kind of sources, then, Mateus Roberto has released the store for TFS 1.4 which you can find by using the search function, or by filtering the posts in the resources section. His source code points to a fork of TFS he has, which would fit your needs.
My recommendation is to teach yourself and develop the skills you are going to need. If you think that you are going to be able to just hop in, with zero experience, and get everyone to tell you everything you need, show you where to find the resources you seek, set things up for you, troubleshoot for you, and you will be able to set up a free money making machine, with almost zero to no effort... someone sold you a lie.
If you are a hobbyist, or someone seeking to learn... and you truly want to be able to handle changes like "adding a game store" to your own client and server, then, I suggest you start by learning C++ and Lua and get a handle on both those languages before coming back to "OT" and trying to figure things out. There is for sure a hard skill gap for entering into this type of "business", and those who are not willing to learn fail indefinitely, those who do learn at least have a chance...
If you start learning, and doing, then you won't be sitting around for a week at a time waiting for someone to tell you what you should do.. and please, don't be afraid to try to help yourself first, before coming here to seek help, because trust me, the help is much more limited nowadays...