Why rehearse? Just lip-synch to canned music. It doesn't even have to be your own. No one will notice.
My cousin's cousin has a studio but in Luohu.
Try Senzhen Music Heaven. It is located not too far from Litchi Park and that big "Seibo" shopping mall on Shennan road in Futian. Add me and I will pm you the managers number. Let me know when you guys are ready to gig. I might have something for you.