Sam, if you want the approach plates, just buy a decent touchscreen tablet PC and load Jeppview/Flitedeck on it. Peter already mentioned Motion LS800, I'd vote for Lenovo X61 or Fujitsu P1610/P1620 depending on the size you want, and I'm sure there are other decent ones. This way, you can get not only a MM GPS, but the entire electronic flight bag of any complexity, plus a stowable keyboard.
And the ability of Jeppesen to superimpose approach plates on top of the nav chart is a really nice feature.