I would give Motion a try. I used them for their trial and really enjoyed it. I'm considering paying for the product now. It's at usemotion.com

I'm sure it's flexible and if I put time into it, I could solve all my issues, but the thing I didn't particularly love was that you needed to remember to mark a task as done when you completed it. If you didn't it would keep showing up at other open calendar times. Other than that, it did a great job and making sure I prioritized my most important tasks.