That JY-MCU bluetooth module is a pretty good choice. I have a couple of those and they work great.
I got mine from here, but it's probably the same or very-similar hardware:
What are you going to be doing with them? This device is a simplified slave-only serial module. You set up the name, pin, and baud, and that's all. You need to use a master-mode bluetooth module to connect to it (an Android, PC, or different piece of hardware). You cannot connect two of these modules to eachother wirelessly (they don't have any way to scan or connect to another device, they just accept connections).