i would use a switch such as belkin gs105/or gs108 in place of the other router it has 1 gig capability
that is what i am using with my dir655 and seems to work well, i also use network magic to monitor my network i have 3 pc's , 1 dvr, 1 server, 1 wii, 1 blueray, 1 printer
i connected the pc's and printer to dir 655 used 1 port to connect switch and connected remaining device to the switch