Are you certain Zeta Tau Alpha doesn't have an out of the box product ready for you to customize? I know Alpha Xi Delta uses a great program (which I'm blanking on right now) and it provides a professional and thematically consistent product across all (or most anyway) of our collegiate chapters. And my alma mater provides domain access.
And I would say that although Facebook and
Twitter are important, I would still have a good, thorough and CURRENT website available for lurkers, incoming college students and their mothers.