Charities are always great for PR. Toga parties are not. Think more along the lines of jackets and ties, flowers, and kids. This is conceptual, you'll have have to come up with the final ideas yourselves.
Good luck with that and congratulations! As IFC President you have a lot of responsibility regarding PR on campus and to the general public in the area. Set your goals high and don't be afraid of sounding nerdish.
If 'nerdish' is not a word, then I just coined it. If Earp can do it, I can do it.
ZAX,
Jono