Mate in four!  I had to make revisions due to confusion.

Why not just Nf6+, pxn, Rg1 (or Qg3) mate!  Mate in 2 would be more efficient than mate in 4, correct?  In puzzles like these, I would think that the shorter mates are the ones that we're all looking for.

Yes, mario's suggestion was the first line that came to my mind as well. It still speaks as a strong puzzle, even though yours is much prettier. :)