Looking for good US retailer which accepts UK credit cards

The credit card address mismatch will spook a lot of companies. I have no problem using my credit cards to import items from the UK, but my address matches my card. All you can do is call (with a phone...) the on-line vendor you want to buy from and ask.
I live near Chicago and there are numerous places to buy computer equipment at relatively good prices. Sale prices are cheaper than the normal internet price, while normal prices are a few % higher. In the mighty NYC you should be able to do as well or better, except for picante sauce.
I only know of J&R music world as a NYC vendor, primarily as a HUGE audio and video vendor. They also sell computers and related parts. You may do better elsewhere, but they will be cheaper than UK pricing.

If they accept your UK card, it shouldn't be a problem at all. As long as your billing address matches the address on your card, they should accept any shipping address. This is how you buy gifts online, remember.

Shouldn't cause a problem. I work in a building with xray security at every entrance. My PDA, MP3 player, and cell phone go through every morning, without any issues.

If they accept your UK card, it shouldn't be a problem at all. As long as your billing address matches the address on your card, they should accept any shipping address. Merchant Account Services