Integrated Curricula - the Good, the Bad, and the Ugly

In working out the details of the Upper School Math curriculum a few weeks ago, we came to a consensus that things would be much more interesting, relevant, and connected if we created an integrated sequence of course that combined the curricula found in geometry, algebra 2, and pre-calculus classes, along with an infusion of statistics, probability theory, programming, and fun math things that are not usually found in standard high school math classes.

After high-fiving ourselves for a bit, we realized that going down this route answers a few questions, but creates about a zillion new ones. Such as, where do we place new students who have already taken one or more of the standard high school Math courses? 

Do we teach all students the same integrated content or do we create "regular" and "accelerated" versions? If we teach the same content to everyone, how do we allow for sufficient support or challenge for students who are either struggling or need more? How do we match up our crazy courses to the standards expected by the University of California board for accreditation? If a student transfers from our school to another one, how will the new school be able to place her into their standard system? How can we convince the rest of the school community that these courses are going to be awesome and worth the hassle?

Apparently, integrated math courses have a reputation as being fluffier or geared towards struggling students (news to me), so we will also have to communicate clearly to everyone why we are advocating for this and how they will benefit and challenge students.

The other issue that is quickly coming to light and making it obvious to me why more schools aren't pursuing this option is how demanding it is of teachers' time and knowledge. Despite my education and teaching experience, I'll be the first to tell you that my knowledge of statistics and programming is pretty minimal. Trying to write either of those two things into the curriculum is a major headache for me... I can lecture on some terminology and have students do examples and exercises, but I don't have the depth of knowledge to write a really awesome activity or project that will be rich and student-centered and exploratory and all the good stuff that I want to be doing in my classroom. Teaching integrated courses requires the teacher to have a much wider net of knowledge and the fluency to weave that knowledge into their teaching. This is really, really hard. 

I feel like non-traditional curricula have more room to go farther in either direction... they can be really, really awesome and exciting and students can learn a ton. But if done badly, they can leave students (and families) frustrated and with large gaps in their knowledge. There's less of a ceiling, but also less of a floor. And that scares me a lot.

People who teach integrated classes: any advice?