I like idea #1. Its similar to donkey betting but i look at donkey betting being like buying a cheap scratch card with small prizes, While this would be like buying a more expensive scratch card with much higher prizes.
My only fear about it is that as a progresive prizepool it might not grow that much as it more that likely will be won every freeroll. My only idea to solve this is to limit the number of bets allowed each tourney to 30-40 so there is a chance that the jackpot can go inclaimed for a few tournies so it rises to a high amount