I use a normal desk with a keyboard tray clamped to it, and it's certainly not the most elegant solution. I would like to have a desk that has a sliding tray for my controller keyboard (Nektar Impact LX88+), but it's nearly 51 inches long, and I think only the super-expensive Platform desks can accomodate that.

Here's the desk and keyboard tray I bought. And here's my setup.

The desk has an attached frame, and you'll have to clamp your items to that, instead of the desk itself. It has three length variants: 47-inch, 55-inch, and 63-inch. The top of the keyboard tray sits about 2 inches below the frame of the desk.

Personally, I wouldn't put an 88-key keyboard on any type on a stand. I think a keyboard of that size should be placed on something large and stable that won't budge or get pushed over from movement or pressure. But desk options are rather limited for those of us with 88-key controllers (those with 61-key controllers or smaller have a few more choices).