I need to actually sit down and write this up, but here is what happened:

1) Disabled the Actiontec M142(something)'s wireless signal
2) Put my old WRT54GSv2 on the network
3) Installed DD-WRT v23 sp2 on the WRT54GSv2
4) Boosted the signal
5) Attached two 125% sized Windsurfer Parabolic Reflectors to the WRT54GSv2 (Sarah helped me to print/make them)
6) Replaced Sarah's WUSB54GS with a 6dbi gain antenna attached to her internal ZyXel 302 (the signal is more consistent, now)
7) Set up Q0S to assign priority to specific services (VPN, FTP, XBL, SMP, etc, etc, etc) and prevent the network from being flooded by other, more hungry services at peak hours
8) Made sure that Video On Demand with FiOS still works, as well as channel listings and guides

Left to do:

1) Add a wireless card to the G5
2) Move the router to a more agreeable position, as one side of the house has lost quite a bit of signal after adding the Windsurfers
3) Play around with boosting the transmit power on the WRT54GSv2
4) Figure out a way to further boost Sarah's signal (probably extending the gain antenna a few feet, have to find low loss extension/arrestor cable)