You might want to combine Geiser with Quack[1] for best result with Scheme. Also, I think it's worth a shot to have a look at the fairly new Racket-mode[2] written by Greg[3]. Geiser + Quack are rather old and for Scheme in general, Racket-mode focuses on and is tightly integrated with Racket.
[1] http://www.neilvandyke.org/quack/ [2] https://github.com/greghendershott/racket-mode [3] http://www.greghendershott.com/