Is there a site we can go to search for a patent of a certain product?

[bcnu]

What do you mean "international patent"? A patent is either enforceable in your country or it's not. The only "international patent" I know of is the "European Patent" that can be used to obtain protection in all of Europe, but only if the applicant has paid the annual fees in each country. Similar rights exist under PCT, but must still qualify for issuance of an individual patent in each selected country.

Google.com/patents is a much easier search engine than the one at the USPTO.gov/patents website.

If you're going to "claim" something in your own patent, you would have to be concerned about any publication in any language in any country, and public use, and any equivalents, not just the currently enforceable patents in your particular country.