But they have different Mbps values which one would be suitable?
That is the speed they operate at, the figures are usually very optimistic. As IMJ says, 500 would be suitable. There are a number of different types of configuration, some have more than one Ethernet socket so multiple devices can be connected to one adaptor. Some have a 'plug through' facility which means the adaptor can also be used as a normal mains socket.
Your set up will be similar to this