Some shops in Golden Plaza was bad and even local residents would not rent any attire from them.
I'm heard that this shop is good. http://www.koonnamwah.com.hk/qungua.html
On this webpage, the pictures show kua for the couple (PHoto A-I), some pajamas (Photo O)and even kua/traditional clothes for parents of the couple (Photo K-M), etc. Kua in Photo A is the most luxuary one.
I've heard that kua could cost HK$3xxx for even more. If yo rent it, it could range from $500 to $2000, depending on the pattern on the kua and whether it's new.
There's a tip to wear kua. The bride needed to wear a medium/short-sleeve pajama (upper part) underneath the kua. It's more comfortable for her to wear it. In Chinese tradition, people would not wear the whole set of kua before the wedding day/banquet. They would wear either part of it in the shop.