There is no shortage of keyboard controllers available, and if you need something very inexpensive and smaller is okay, you should have no problem finding what you need.
However, if you want a keyboard with a better quality build, great feel and excellent software package, I can highly recommend the Keylab 49 MK3.
Highlights are the keyboard does not feel clicky compared with some smaller models, the display is excellent, browsing is easy, the arp is a step up from anything standard and again; the sound options that are included are tremendously broad, and even nicely customizable, if not quite to the point of this keyboard being labelled as a sound designers dream.