Since you already have Linksys product, why don't you look at their website, for additional hardware.
Just for your information, using a range expander might reduce the speed on the second half signal...
i.e.:
AP --> (Full Signal) --> Range expander -- (Half speed) --> Devices that connect to the Range Expander.
I just moved my Tivo Series2 a little farther from my Moto Wireless SBG900 b/g cable modem. I have a Linksys b adaptor on the Tivo USB port and I just ordered a Tivo supported g adaptor online. Before I moved my Tivo, I was getting excellent reception (above 90%) and now I get around 20-40%.
In addition to the g adaptor that I just purchased, I would like to extend or boost the signal. But after looking at the DLINK DWL-800AP Extender, I'm now worried about the comments I found about it as found on the product web page:
** Only Repeats the Wireless Signal of:
1- D-Link AirPlus Xtreme G? DI-624 Wireless Router - Firmware 2.37 (Rev.C) or newer.
2- D-Link AirPlus Xtreme G? DWL-2000AP Wireless Access Point - Firmware 1.56 (Rev.A), 2.06 (Rev.B) or newer .
3- D-Link AirPlus Xtreme G? DWL-G800AP Wireless Range Extender.
So, I am pretty sure that I need a G repeater to improve my signal but given DLINK's restrictions, I'm not sure which product to look at for boosting my g signal to my TV adaptor.
Any thoughts or recommendations?

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic