To buy the British Edition or American edition?... HELP!!!

I have read the UK edition of harry potter about one hundred times. We are Australian.

My brother now wants to read them. he is 11 years old and I want to buy him a boxed set. The childrens edition boxed set is white and (i believe) makes the book look boring.

I have found an American Edition boxed set and the artwork on the book covers and the box looks fantastic and will really draw the attention of an 11 year old.

I know to not judge a book by its cover but an 11 year old doesnt think the same way.

My biggest issue is the difference between the books. Has anyone who is not american found any confusion between the editions. I want my brother to enjoy the books as much as i do but i am concernced about the difference in the editions.

I know words are slightly different but is the overall effect different?

please help...