Costco is another good place to get foreign foods and other stuff in Kansai. It is located in Amagasaki which is about 15 minutes away from Osaka (Umeda) on the JR Hanshin Line (between Kobe and Osaka).
Costco is good for some things, like buying in bulk, but if you are looking for just a few items it may not be worth the effort.
Where Costco shines is in the goods! If you are looking for items other than food, then Costco will be the place to look and as always the prices will be quite reasonable.

Expat Express is an online ordering company based in Utah, USA. Their website says they have service representatives in Japan, and will ship to a whole host of countries. Their product selection is wide (as one would expect since they are based in the USA).
The Foreign Buyers’ Club was started by Chuck and Kelly in Kobe over 12 years ago. They now have in addition to the USA club, British and Aussie websites.