Go to Aramex.com. You'll get all the info you need there.
When you register for Shop & Ship you get a US mail address which you can use to ship stuff to from online shopping sites. Then Aramex will deliver the items to you.
The prices you get from the Rate Calculator are excluding local customs, which will be decided once the stuff comes down here.
Note that to use Newegg.com, you will need a Credit Card issued in America. And the Shipping address has to be the same as the billing address of the card. So it's a bit of a pain. But I think other sites such as Tigerdirect accept local cards. buy.com and amazon do for sure.
I also came across some sites that ship to SL directly. The links are on my office computer tho. Will post them tomoro.
