[eckso]

I can recommend Gianluca Barbaro’s books, found here.

Vol. 1: Play Melodica with Both Hands! Japanese Style
Vol. 2: Melodic Intervals Workout

I have been working through vol. 1 and recently ordered vol. 2. The exercises and fingerings are quite helpful. It has useful tips for developing good playing habits from the start. The binding and paper seem to be quite good quality. They may be somewhat less quick and easy than the Suzuki books.