In the customer service sections of their websites, essencompu.com, newegg.com and ateck.com state that they do not accept international credit cards:
essencompu.com:
"We cannot accept:
* Personal checks
* CODs
* Credit cards registered outside the United States, Canada, and Alaska."
ateck.com:
" Paying by Credit Cards
We gladly accept Visa, MasterCard, Discover, and American Express credit cards. Please note that we will only accept credit cards issued by a bank or other financial institution within the U.S. with verifiable references."
newegg.com:
"What method of payment does Newegg.com accept?
• Visa
• MasterCard
• Discover
• American Express
• Prepaid Company Check, Personal Check, Cashier Check or Money Order
(Note: All Prepaid Orders will take longer to process due to all checks must cleared, including Cashier's Check due to the existence of fraudulent checks.)
• No Purchase Order, Fax, and C.O.D. orders please.
Sorry, No International Credit Card.
End quote
If this wrong please let us know.
ibuyer.net is a search engine like pricewatch, they do list those that accept international orders, however, this usually means international shipping, not necessarily that they accept international credit cards (money order, US$ bank draft).
I have bought from, aclcomputers.com (you must fax authorisation for skybox), pcinfinity.net (I think their policy has changed since) and USSA.com, however stay away from them, see resellerratings.com. By the way amazon.com sells computer hardware, although their options are limited.