I like Macs, just not the ones the schools buy because they always get the lowest quality ones. I ended up putting RedHat7.3 on my computer(200mhz P1 w/MMX), it was great for what I needed it to do, with the exception that it couldn't do anything I wanted it to do because I simply didn't have the hardware. Had my father given me permission to install RH or any other major Linux distribution, on our decent computer(1.7ghz P4), I'm sure Linux would've run perfectly. I also had problems getting my network to work for my linux OS, never got it to work under it, but it works under ME, so that's what I'm going to end up using until it dies.
So, to bring this back into the topic, the Mac OS's are based off of the Linux kernel now, so if you really want to have the stability and everything(Even on my 200mhz computer, Linux NEVER crashed on it!), you could try Linux. Make sure you get a window manager though(like KDE or Gnome,) or else it'll not be as great as you want.
If you want an office suite that works well compared to Microsoft's, then you could try FreeOffice(I think, not sure.) It's basically OpenOffice5.0, but free. OpenOffice use to be free, but now they charge something like $70?... Anyway, it's a lot cheaper than getting Microsoft's office, and I think they give you a powerpoint program too, which would be the equivelent of a Professional package for Microsoft with all the types of programs included? Just some food for thought
*Please note that if you attempt to install Linux on any PC and something does not work out by a freak chance, I am not liable, and that you underwent your operations under your own free will and accept all responcibility.