Rikki:

When you find out that most of the popular MIDI controller boards weigh less than 15 lb. (in 61-key form) and even less in 25 or 49-key forms, you may be more interested (mine weighs 7 lb.). Also prices (discounted) in the range of USD$100-$300 for very capable boards. I chose the 49-key form because it fits most desktops or typing desks without throwing everything else out the window, and still has room for all the controller knobs. And it is so light I can unplug the USB connect and move it instantly.

"Audio" is not built-in, however -- as in full or partial arrangers. There is no sound chip in controller keyboards. Every sound is dependent on your sound card and MIDI software connections. Such as OMB.

There are many competing brands of MIDI controller boards. Go online and look at M-Audio, CME, E-Mu, Korg, for examples of popular choices. Download any manual and you will see a variety of controller key-knob-slide combinations available. There are a few reviews on Harmony Central and elsewhere -- not as many as would be useful, unfortunately.

PS: here in the US it is "noodling" -- (from jazz players' use of the term years ago); "doodling" refers typically to little drawings made on note paper, during meetings, etc.