How long does it take to get the code?
Depends. Most will say that it's usually within 24 hours, and can be even less. Rarely there are hangups and it can take longer, or won't work at all, but they usually refund your money. Just make sure when you check out they usually request you include the IMEI number in the message at checkout, so don't forget that part.
Maybe Apple is forcing people to buy a European version ? Is there any such thing ?
They're not forcing people. There is a European version, and its sold in Europe
. They don't have use for certain American LTE bands so they don't have them, and most American's don't have use for European LTE bands so we don't have those. From my understanding the technology is still cost/size prohibitive to include all bands on a single chip, thus the multiple versions. They therefore have regional versions. If you're trying to get a cheaper model then don't be surprised not everything will work at the highest possible speeds. Still the American model seems to be the most robust (Sprint version a little more so, though I don't know about their unlocking).
Here in Israel we have to 'suffer' without 4g, but it doesn't bother me so much for now.