I currently have a huge Ikea desk that my husband raised with slabs of wood between the desktop and the leg supports - but before that, I bought a "bistro" height bar table from Ikea (here's the model I used: http://www.ikea.com/us/en/catalog/products/S19834379) that was perfect. I'm 5'4" and my arm height is level; it's a little short for my 6'4" husband, though.

It was the cheapest ready-made option I could find, but you could get lucky and score on Craigslist.