From your first reference image, it looks like his tie has a striped pattern (see the larger Ocelot on the left).
As for the shirt, it looks to be black. If you can, play through some of the cutscenes. I found the ending of the Middle East here, Ocelot at 3:00...
The coat looks like a matching set with the pants, so look for them as a set. Try a military surplus store for something with a more military/officer cut. The black straps actually look like the hold his coat closed, instead of being a harness worn underneath.