Peaches -
for the "entry level" equipment such as linksys or dlink devices, the distance isn't the only issue... ELEVATION will also play a factor... and you seem to be dealing with a bit of a grade in that location... Honestly, I don't think a 75$ WAP and a card in your laptop will do what you want... you need a much more robust setup - like something from Buffalo Tech -
http://www.buffalotech.com/wireless/index.php - they make "outdoor" equipment - which it seems you will need...
