Wireless hardware recomendation, 2 points 300' with line of sight and 120' with line of sight

I am not very experienced in wireless so please bear with me.  I have a site that would like to share their DSL connection with two outbuildings.
The main building is a construction trailer with a standard DSL plan, with a unknown wired router and a Netgear WGR614V6 already installed.  (I'm assuming that will need to be replaced or augmented with something else)

I would like to get this signal to two other locations, I am guessing each building will need an access point but I will let the experts let me know what I need)

The first is a building is 120' away from the main building, corrugated steel siding, steel frame construction
The second is a garage 300' away from the main building, vinyl siding, wood construction.  The computer is located in the basement of this structure so I will need a pretty good access point to make sure the basement computer can get this signal.  (located about 50' away inside the building from the garage line of site)

the good thing about this site is that both buildings are in view of the main building and about 15 degrees apart from view of the main building.
a VERY crude picture is located here http://solarbyte.com/wireless.jpg   No laughing please :)

I am assuming I will need to attach some type of antenna to the exterior of some or all of these buildings.  What is the best/cost efficient hardware for the job?  (my main supplier is newegg.com, if you could pick from their selection that would be most helpful)

Thank you!