Alesis Q49 49-Key USB MIDI Keyboard Controller: http://www.amazon.com/Alesis-Q49-49-Key-Keyboard-Controller/dp/B0038YX3BS/ref=sr_1_1?ie=UTF8&qid=1433880340&sr=8-1&keywords=keyboard+usb+-+midi+49+keys
M-Audio Keystation 49 II USB Keyboard MIDI Controller: http://www.amazon.com/M-Audio-Keystation-49-Keyboard-Controller/dp/B00IWWZAM6/ref=sr_1_2?ie=UTF8&qid=1433880340&sr=8-2&keywords=keyboard+usb+-+midi+49+keys
Novation Launchkey 49, 49-key USB/iOS MIDI Keyboard Controller with Synth-weighted Keys: http://www.amazon.com/Novation-Launchkey-Keyboard-Controller-Synth-weighted/dp/B00B9QONQQ/ref=sr_1_4?ie=UTF8&qid=1433880340&sr=8-4&keywords=keyboard+usb+-+midi+49+keys
M-Audio Oxygen 49 IV USB Pad/Keyboard MIDI Controller: http://www.amazon.com/M-Audio-Oxygen-49-Keyboard-Controller/dp/B00IWU2CBA/ref=sr_1_7?ie=UTF8&qid=1433880340&sr=8-7&keywords=keyboard+usb+-+midi+49+keys
Este me parece muy buena opcion que piensan ustedes
Alesis V49 49-Key USB MIDI Pad/Keyboard Controller: http://www.amazon.com/Alesis-V49-49-Key-Keyboard-Controller/dp/B00IWWEW20/ref=sr_1_13?ie=UTF8&qid=1433880340&sr=8-13&keywords=keyboard+usb+-+midi+49+keys
Nektar Impact LX49 49 note USB keyboard controller with pre-mapped integration for Cubase, Digital Performer, Garageband, Logic, Sonar & Studio: http://www.amazon.com/Nektar-LX49-controller-pre-mapped-integration/dp/B00GA99CCW/ref=sr_1_19?ie=UTF8&qid=1433880821&sr=8-19&keywords=keyboard+usb+-+midi+49+keys
E-MU Xboard 49 Professional 49-Key USB/Midi Controller Keyboard: http://www.amazon.com/Xboard-Professional-49-Key-Controller-Keyboard/dp/B000A31PUG/ref=sr_1_21?ie=UTF8&qid=1433880821&sr=8-21&keywords=keyboard+usb+-+midi+49+keys