Beer o clock,
Its a matter of what you prefer. I was in LA and bought my car there.
You should either find someone who can find you a car over there or go yourself. I have heard good and bad stories about trusting someone else.
Either way, buy your car from LA. It is easier to transport home and they never used salt to break up the ice on the roads like some other states so the car is less likely to be rusty.
The codes are just the VIN number. It will tell you where your car was made, what year etc etc and importantly what engine it left the factory with.
For example if you here someone say it is a C code car that just means that car left the factory with a 289 2V V8.
There is a lot more you can tell from the VIN and also the tag on the LH door jamb. (if they still match...)
If you spend some time going back through the old topics in this forum you will learn alot.
Good Luck.
James.