I've been thinking and I'll be hosting world's first Bitcoin lottery!

We'll be using the last two numbers of a real lottery, which one I do not know yet. (Maybe one that we can check online?)
When you'll buy your lot, you'll "bet" on a number between 00-99. (including 00 and 99 ofcourse!)

So, who's in for it?
What real lottery should we pick for our random numbers, or does anyone have a better source?
What price of the "lot" sounds preferable? 50 BTC? 25 BTC?
And what's the maximum amount of lots I want to let people buy? 3? 5 at most?

Please note that if the "jackpot" doesn't "fall" (no one wins), I'll keep hosting rounds until there does win someone, and I wont play myself.
So I want like a lottery that draws numbers every week if we can't get one that draws every day.