chris,
don't get caught up in all this worry about marimba range and available literature. The best marimba out there is the Alesis SR16. Dude, it's got 24 bit stereo sound, reverb, ambience, 100 presets, tones of samples...i don't really know if there's much marimba literature out there for it, but i do know that the great masta'G-money Stout used it on his new rap album, quote: "The Alesis SR16 is a back kickin' beat droppin' box-o-booty movin' ya'll better get down machine FOO!". (ya'll hear that groove on the track Rumble Strips, yep SR16) i hope this extremely insightful message helps you in your dession chirs.
peace and power to the brotha's

sorry to spoil the joke, from the gifted in-DOAH!-vidual who posted the last message. The Alesis SR16 DRUM Machine
is only 16-bit stereo, and although a classic in the world of MIDI, it sadly is about as capable of sounding like a marimba as you are of writing something funny! Asshole!