Yeah, Ubuntu would be a great solution, but that's going out into a whole different category and support-wise, you are up the creek in all likelihood (plus, I'm not sure what your networking situation is with work, but that's a potential consideration, too). There is a lot of software available for Linux in all flavors of OS, but you'll inevitably run into several things you'd like to have installed and are not going to want to reboot to use. Virtualization (available on many platforms) means you can access both OS's [or more] without restarting).
Also, it's worth pointing out that office on mac does not cause a mac to crash, it causes the software to crash. There's a big difference between a kernel/OS/machine issue and an application issue. Regardless, it's true that linux will be more stable on all fronts, but I can count on one hand the number of times I've had a Mac crash or become unresponsive in the last 5 years (although I can count on about 250,000 hands the number of times I've had software crash on it).
Yep +Tim Wilson
I'll be in NYC, looking forward to it!
I'd probably recommend starting with MS Access or Filemaker pro, rather than dealing with a less user-friendly DB solution to start with. You'll get more functionality than Excel could ever handle (and speed on a factor of 100's X), but you won't have some of the BI stuff like you mentioned. If you need data visualization, that can always be brought back into excel or you can invest in BI as you see fit (I like Qlikview a lot). And you can import all of your current data very easily.
You might also want to check out Roambi for data vis. Although the formatting of data can be a total pain in the ass (made much easier when you use a db), it's gorgeous visualization software on iPhone and iPad that stakeholders just drool over.