Here are a few links for Vintage shopping in Manchester:
There's also a couple of other vintage shops on Oldham street as well as the designer oxfam.
There's also a COW vintage in a different location- (http://www.yelp.co.uk/biz/cow-manchester) I've never been to the Manchester one but the birmingham one in digbeth is pretty cool :)
As for bars a clubs it depends on what you're into.
There are a collection of really nice bars directly opposite Deansgate Train station (making them really easy to get to)
Font bar is fabulous for cocktails which is situated near oxford road Train Station, 5th avenue is a good alternative place to go, as is 42's (42nd street), for somewhere swanky, the Hilton Hotel (Deansgate) is meant to be fabulous, and for a nice little range of bars and clubs all under one roof there is The Printworks, which is right by Victoria Station, which caters for the masses.
I hope this helps.