Case that uses the existing bluetooth keyboard

I'm looking for something like the Zagg case, but I already have an Apple bluetooth keyboard and was wondering if there is anything (affordable, ideally) out there that is similar to the form factor of the Zagg. I would purchase one of those small stands, but they would not seem to work that well in a lap typing situation. Currently I just prop the iPad on my crossed leg, but would like more options, short of surgically modifying myself. Thanks for your input!