I did exactly what you are doing.... Except.....
I started with 3 machines.... 1 main machine, 1 kids machine, and 1 fileserver. Wanted to move the fileserver downstairs into the basement. So, I got another hub, went to Home Depot and got:
100' roll of CAT 5e,
(2) 4 position cover plates,
(2) RJ45 snap-in sockets for the cover plates,
(1) Cable snap-in connector,
(1) Blue plastic single gang box for the basement
(1) "boxless" adapter for the office to attach the cover plate to (This just goes into the hole you will cut, and gives you something to screw the cover plate into
(1) bag of "blank" cover fillers, to cover the extra holes in the cover plates.
Went up into the attic and pulled the wire from the office (where everything was). Then I found my utility shaft for the heater & hotwater exhaust, and dropped the cable down there. (This is on a 2 story house w/walkout basement, which is why the 100' of CAT 5e). Fished it out into the utility room in my basement, and ran the cable through the box rafters to where I wanted the plug to be. Then I attached the single gang box to the wall, and ran the CAT 5 cable into the box. Wired the RJ45 plug as indicated in the instructions, snapped it into the cover, and attached the cover to the gang box.
Went back upstairs, and put the "boxless" adapter into the wall, wired up the other RJ45 plug as indicated and snapped it into the cover plate. Also put the Cable plug into the cover plate and hooked up my Wireless Broadband. Then I screwed this cover plate onto the boxless adapter. Then I ran a normal Cat 5 patch cable from my upstairs hub to the plug I had just wired up.
Went back downstairs, and ran a Cat 5 patch cable from the downstairs plug to the uplink port of my new hub, and walla.... Everything worked first time out....
Expect 2-4 hours to do this job, depending on what kind of contortions you have to go through to get the wires where you need them, and what kind of access you
have to your different rooms where the cable needs to go.
Remember where I said I started with 3 machines. I have now grown that to 2 machines upstairs, and 6 machines in the basement. 2 are duallies, all 6 in the basement are dedicated full-time to Folding@Home, and the 2 upstairs machines do Folding@Home in the background.... So beware, this project can get away from you in a hurry.......:Q