Jazz with less horns??

Chick Corea, Bela Fleck and the Flecktones, Thelonius Monk, Herbie Hancock, Martin, Medeski and Wood

Jon Hassell plays synthesized trumpet and doesn't seem horn...y at all rather than fully electronic.
Andy Summers(Police) - The Last Dance of Mr X .
Brand-X is a fankomenal blend of famous musicians that you might like. Solos are maily performed by synthesized fretless bass by Percy Jones(a piece of virtuoso indeed)

Guitar and bass:
Marc Johnson
Kenny Burrell
Charlie Hunter
Bill Frisell

Piano:
Carla Bley with Steve Swallow on bass
Lynn Arriale
Eric Reed
Bill Evans (the piano player, not the horn player)

Art Pepper, sorry, he plays alto sax but may change your mind about no horns. My personal favorite.