1. I think what you are trying to do is to setup a STATIC IP on these computers. You can log into the Router web portal configuration page via 192.168.1.1 and then go to the advanced tab --> ip address distribution --> connection list --> this is where you can assign STATIC IP to your machines.
2. Transfer rate between hard drive to hard drive are considerably slow. Most likely transfer rates within Home LAN network should be less than 50mb. Not sure what you are trying to do. Transfer data between wireless are extremely slow.