any church to recommend for wedding?

There are so many churches, it's hard to suggest one. You could start locally, find out what parish you belong to geographically and ask there. If you are not a member of the church (which I guess you're not) you will have to pay for a wedding. Maybe you can become members before you get married?

Other than that, what preferences do you have? How many guests? Do you want a big impressive church or a small intimate one? Same for the restaurant - how many guests, do you want it to be exclusive or affordable, do you want to book tables at a regular restaurant or do you want a party venue separate from other guests?

As for marriage licence, you will definitely need one and I don't know how difficult it will be to get. You will probably have to get some papers from China too. The embassy should be able to help you with that information!

Oh I know who you can ask! There is a "University Church" that holds simple weekday services and are available for counseling. There is a room for religious services on campus, but I think it's probably too simple for even a low-key wedding. But you should ask the priest there:
www.universitetskyrkanstockholm.se/helena.php
www.universitetskyrkanstockholm.se/english.php

The Engelbrekt church (which I think is the parish the university area belongs to) is maybe a bit too big, but there is also a church in Hjorthagen which looks quite nice. I doubt that there are any good restaurants nearby though, but perhaps you could all go to Värtahamnen and get on a 23-hour cruise to Finland instead!