The iTunes, iBooks, and App Store languages are not controlled by the language setting on the iPad. They follow whatever country's iStore you are logged into. This is controlled by your Apple ID. To have the stores be in English you will need an Apple ID from an English speaking county.
There are several threads on getting an account in a second country. I don't have any of the links handy, so hopefully a search will do the trick (try the custom Google search at the top of the website), or another member will have it handy.
This is the only part I have handy. You may need an address and email address compatible with that country for the method to work.
Creating an iTunes Store, App Store, iBookstore, and Mac App Store account without a credit card
Once you have your new iD, from the U.K. I'm guessing, go to the bottom of the page in the App Store. On most tabs you will see three buttons. The left most button should either show an Apple ID, or say Sign In. Tap this button to sign out, if needed, then tap it again to sign in with your U.K. Apple ID. You need to do this individually for the four iStores: iTunes, App Store, iBooks Store, and iTunes U.
Be aware that once you have more than one Apple ID you need to keep track of what you get using that ID. All content is tied to it. In order to update or re-download content for free you must be signed in with the right ID.
