To my knowledge, getting a car approved in one country means it should get approved in any other country without technical alterations.
Now since I've seen this post around a few times, I recall you're going to Germany, which is (as I've gathered) one of the more easy countries to get an approval. Thusly a lot of cars get exported to Germany, approved there, and then exported onward to a country of destination, which can't complain too much about the technical state of things, because it's already had an approval.
The dr-mustang.de forum has a lot of info regarding imports and regulations on the subject:
dr-mustang : die us-car community › Wörterbuch › Import-Zulassung-TÜV
And here is the part about the lighting:
dr-mustang : die us-car community › Wörterbuch
That bit however doesn't specifically note the turn-signal lights, which is the biggest hassle. Now I did track this tidbit:
94/95 Tail Lights with yellow Flashers - Mighty Forums
Basically what was done (and I've seen it over here in NL on a car), is that there are yellow bulbs in the back-up lights. Now at the lowest part of the rear-bumper two additional lights were installed, namely a white 'backup' light, and a red 'fog-rearlight'. The fog-light BTW is mandatory.
I'm using this picture just as the example in case:
Putfile - Uploaded Picture
Basically that solution would be the 'quick and dirty, not to mention cheap' way to get the car legal on the lighting bit. Just requires a bit of rewiring...
As to parts... there are shops here, but the majority of those kinds of specifics still need to come from the US.