Which MacBook with Windows? I'm working off a mid 2009 13" MBP right now which I want to replace soon. I'm thinking of getting an MBA instead - I would probably get an 11" for the road, with an external monitor for working at home. 

But here's my problem: I will go back to school this summer and I'm required to use Excel for Windows for my classes (sadly, Excel for Mac won't do, urgh!). Therefore, I will have to also install Windows 8 (with Boot Camp) on my new computer. Will either of the MBAs hold up? (Obviously, I'd go for the highest RAM and hard disc possible.)

Thanks a lot!
Try a Virtual Machine (VM).
1) You own a Windows license: Try VirtualBox (with ExpansionPack). It's free, but you might need a MB Pro because you have to assign at least one CPU-core to the VM.
2) You don't have a Windows license: Try Parallels. Then you can run Windows software from the OSX desktop without having windows installed. Maybe the better alternative but it costs 50$. With Parallels a MB Air should do the job.