I have to say I love staying on Soi 18 as its fairly quiet. Probably not suitable if you want to be right next to Nana, however its not far to Cowboy. This hotel has a complimentary tuk-tuk to take you to Sukhumvit road
There are a few good eateries on Soi18 but lets be honest they are everywhere
I have stayed at Maitria right opposite the Park Plaza Soi18, a really nice 4-star, girl friendly. I want to also try the Park Plaza