For a belt sander, a stationary sander will be much more controllable than a hand-held belt sander. But a hand plane is really fantastic for fitting drawers. With a hand plane, you can even match a bowed case opening so that you have an even amount of reveal around the entire drawer. One possible drawback to using a hand plane is the blowout you can experience at the ends of the cut. To help avoid/control this, bevel the edges of the drawers first and then hand plane the drawer front to fit. Watch the amount of bevel remaining as you plane the drawer front edge. Add more bevel as needed.
Tim
on the neverending quest for wood.....