If I understand you network properly, With a clean install of TurnKey, with no modifications it should all just work (after you set the static IP same as Win server).
No adjustment to Apache config or hosts files is needed (so long as you are only serving one domain). You may wish to tune stuff later, but initially you just want to get it working. Also there is no need to install or configure bind unless you want to run a local DNS server.
Your domain already points to your external static IP so that should be fine. And from what I understand of what you have written, your router already forwards port 80 (and perhaps 443 too) to your Win server's static IP (proven by the fact that your Windows webserver was working).
So all you should need to do is to set your TurnKey server's static IP to the same IP as your Windows server. Then it should just work (so long as there is not a IP conflict i.e. if your Win server is not running).
The fact that you can see the TurnKey server via IP on your LAN demonstrates that it was working ok. All you need to do is ensure that the traffic coming from outside your network is being correctly routed to the TurnKey server. So long as you are forwarding the traffic properly (which shouldn't need adjustment so long as you use the same static IP for TurnKey as your Win server was using) all should be well.
Actually you can test whether it's some domain issue or a networking issue, by browsing to your external IP (93.160.199.202) instead of your domain name. If you can
Personally, before you try Debian, I suggest that you do a clean install of TurnKey to eliminate the possibility that something you have adjusted is what is causing your issues.
Regardless, if you go with vanilla Debian good luck with it. Although I suspect that you will encounter exactly the same issues though. To me your problem appears to be with your network config, not with TurnKey.
It should just work
No adjustment to Apache config or hosts files is needed (so long as you are only serving one domain). You may wish to tune stuff later, but initially you just want to get it working. Also there is no need to install or configure bind unless you want to run a local DNS server.
Your domain already points to your external static IP so that should be fine. And from what I understand of what you have written, your router already forwards port 80 (and perhaps 443 too) to your Win server's static IP (proven by the fact that your Windows webserver was working).
So all you should need to do is to set your TurnKey server's static IP to the same IP as your Windows server. Then it should just work (so long as there is not a IP conflict i.e. if your Win server is not running).
The fact that you can see the TurnKey server via IP on your LAN demonstrates that it was working ok. All you need to do is ensure that the traffic coming from outside your network is being correctly routed to the TurnKey server. So long as you are forwarding the traffic properly (which shouldn't need adjustment so long as you use the same static IP for TurnKey as your Win server was using) all should be well.
Actually you can test whether it's some domain issue or a networking issue, by browsing to your external IP (93.160.199.202) instead of your domain name. If you can
Personally, before you try Debian, I suggest that you do a clean install of TurnKey to eliminate the possibility that something you have adjusted is what is causing your issues.
Regardless, if you go with vanilla Debian good luck with it. Although I suspect that you will encounter exactly the same issues though. To me your problem appears to be with your network config, not with TurnKey.