  The ILC accelerator parameters and detector concepts are still under
discussion in the world-wide community. As will be shown, the performance of
the BeamCal, the calorimeter in the very forward area of the ILC detector, is
very sensitive to the beam parameter and crossing angle choices. We propose
here BeamCal designs for a small (0 or 2 mrad) and large (20 mrad) crossing
angles and report about the veto performance study done. As illustration, the
influence of several proposed beam parameter sets and crossing-angles on the
signal to background ratio in the stau search is estimated for a particular
realization of the super-symmetric model.
