International Cuisine! (Istanbul)

I've been living in Turkey for a year now and one of the things I miss most about the US is the (cheap) international food! Don't get me wrong, I love kofte and kebap, but I would like to mix it up once in a while :) I was wondering if anyone knows of a restaurant where I can find any of the following:

Vietnamese Pho
Mexican Food
Sushi
Thai

Any specific restaurants in Istanbul would be appreciated! Thanks so much!!