You can pick up worchestershire sauce over here without any problems it's in all the supermarkets, well it is on the west coast not sure about the rest of the country.

You can also find HP but it is generally in small stores that have a small english selection, typically there will be a lot of ex pats living in the area, but expect to pay $$$ for it and it's normally all gone past its sell by date.

Your better of bringing your own.