From what I have encountered previously, questions regarding "tabs vs. spaces" and "how wide should a tab be" are generally good ways to start a minor flamewar, so my only advice in that department would be pick one and be consistent.

As for converting scripts (either now or later on), you may want to look at perltidy as a way of converting your scripts to a consistent style. IIRC, it has a number of options for controlling tabs, whitespace placement, line length, and many other options, but defaults to a style very close to that described in perlstyle.