Hi guys! I just found a place and I need to buy a mattress (luckily the place already has bed frames). Where can you suggest I can buy a double size mattress with few options to choose from? I need the smaller one (48"x72" or 4ftx6ft) than that of the one in IKEA.

Thanks in advance for the help!

BTW my place is in WanChai.

A HK Virgin