You are better off investing into an alternative solution to wireless. There are lots of other options out there which are faster and more reliable than wireless.
There are solutions for ethernet over: powerline, coax (aka cable TV cable) and phoneline. All are capable and reliable for use with SD and HD TV with an extender.
But, of course the best solution is running a dedicated CAT5 or CAT6 cable between the 2 locations.
1: Dimension 9200 - Vista Ult, 2.4GHz Q6600 Core2Quad, 4GB RAM, 160GB, 750GB, 500GB USB, Nvidia 8300GS, PVR-150, HDTV Wonder, Vbox 3560, X360, DMA2100
2: HP m376n - MCE 2005, 2.6 P4 w/HT, 1GB RAM, 250GB, 400GB USB HD, Nvidia 6200, Emuzed MAUI, X360