HELP! wireless xbox adapter :S

hi, im getting a new xbox tomorrow and i need help finding what adapter to get. for my computer i had to buy a rangemax negear N usb stick because the router is downstairs and my room is the loft converted.... so my signal is shit unless i use a high range adapter.

i dont think the microsoft adapter will be strong enough to get a good enough signal from my router.

ive searched on google but no help so far. ive turned to the trusted mpgh site for some much needed help.

any ideas? im really buggered about it now lol