Well, it's likely that nobody has that product. Like I posted in another thread, I believe that a WRT54G with the Sveasoft firmware can make the router act like a bridge. I believe it also has more advanced security than the standard firmware. It also lets you really boost the signal - by as much as three times, I think. I'd imagine that if you added those fancy antennas they sell to that, you'd easily be able to broadcast through those walls. I'm sure you'd be fine without the add-ons, too.
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Matt