Forgive me for initially failing to notice your disdain for "cheesy EZ piano arrangements". If you like outstanding charts, I strongly recommend you purchase "The New Real Book" published by Sher Music Co. This is a collection of scores of standards and other classic tunes. (Nature Boy is in this book.) The charts are not sappy EZ charts, but are true to the composers' originals.
As a gigantic bonus, they list the recordings from which the charts are derived in the back of the book, so you can get the record and get some inspiration.
I bought mine in April 1977, and although it is soft and tattered from use, I still find something of interest everytime I pick it up.