Before I go any further, you want to avoid the China Club at all costs. If you're looking for a big room club, check out Studio Mezmor (formerly Crobar), Pacha, or even Stereo which is smaller. Those places will have much better music and crowds. For smaller rooms, maybe check out Cielo, Love, etc. As for the dresscode, jeans and a nice shirt will get you in just about anywhere. It's always a good idea to show up on the early side too just in case.