Phew! Your post’s headline (“I don’t think Tiller is robust enough for me”) had me pretty worried for a second there, @chrisming… 
It sounds like you’ve worked through some the setup and configuration, understand the data structure, and see the power of the platform.
If you’re setting up a budget, consider the Savings Budget, which allows month-to-month rollovers. Most of the setup steps will work the same if you choose to use the Monthly Budget in the Foundation template.
We just released two cool tools for “longer forecasting”. Check out:
Finally, @tom.kermode makes a great point about customization. Definitely use the published templates as starting points and references to make your own dashboards.
Good luck,
Randy