Nana,

If Yaowaraj road is China town of Bangkok, Soi Sukhumvit 3/1 can also be the middle-east town of Bangkok. If you want to feel the odor of urban middle-east Bangkok with the middle-east style restaurants this is the place to be.
Nana is also well known for its Red light District, Nana Plaza Sukhumvit soi 4 to be more accurate. Nana Plaza a complex of many strip bars, full of interesting and colorful bars, some even have glass floors that you can walk on but usually it is for the dancers. Though not as famous as Soi Patpong, it is targeted more towards local foreigners with friendlier staffs.
While in the area either visiting the middle-eastern restaurants or the red light areas there is always an option for shopping. Bangkok and major tourist destinations always have this type of small side walk shops. It is all packed along side of Sukhumvit road from Nana to Asoke. You can buy watches, bags, souvenirs and clothing. Taylor made cloths may be another choice to get in this area. Many reputable Indian tailors are near the Ambassador hotel.