I don't know of anyone on this site that speaks Turkish. I have some other ideas, however. You could go to a Turkish restaurant near where you live and ask someone there how to write good luck in Turkish. The Turkish restaurant could be found in the yellow pages or online super pages.

There are certain areas of large cities that being ethnic enclaves and if you can find where the nearest Turkish community is, you can go there and easily find people who will help you.

Many times colleges and universities have students from around the world and they form groups with the education facility. If you can find a college or university with a Turkish student group, I'm sure they can help you.

If you only need a translation of the simple phrase "good luck," you should be able to get an accurate translation from Google Translate. I put the phrase into Google Translate and got this result:
Iyi ?anslar.

Try this site:

http://www.turkishlanguage.co.uk/dailywords.htm

I'd take Hot Guru's advice...in some languages there are many, many phrases that could be used. The simple "good luck" in English may be difficult to translate into an appropriate Turkish phrase.

There may be a much better alternative than a simple good luck as well that a Turkish speaker would be able to give.

Look for the language department in your local college or a nearby university online and get their phone number. Give them a call and explain what you are looking for.

Also try your local library or the New York Public library's information desk. They're supposed to know everything at the NY State library.

Here's the link with a phone number. I hope this helps. I'm sure it will mean the world to him to have that card with him.

http://www.nysl.nysed.gov/contact.htm

Thank you all for your suggestions!