60 card decks with 15 card sideboards. Up to four copies of any card other than basic lands and any cards which explicitly state otherwise. It is 1v1, but that doesn't mean you can't try multiplayer.
I think this would be the best setup, but anyone should feel free to suggest something that might work better.
I was also wondering if we might want to do a points system similar to canlander to limit the power level of decks by restricting usage of too many powerful effects in a deck.