Both OS X and Linux fit what you are looking for.

Linux would let you use existing hardware. There are lots of versions to choose from (Ubuntu is good for beginners) and the sheer number of programs available is mind blowing.

OS X requires you to purchase Apple hardware. OS X is far more windows like than Linux (actually, IMHO, OS X is a vast improvement over MS Windows and it does a great disservice to OS X to even compare it to MS windows). You will have MS Office and most of the big commercial software (adobe etc) available to you in OS X.

With both OS's you can either dual boot with MS Windows or run MS Windows virtually (allowing you to run both OS's at the same time). You should also be able to connect to the windows domains without much trouble.


OS X would have the greatest startup cost, but is in may ways (let the flames begin) far superior to Linux for beginners (OS X pretty much has everything you need to start with and it does just work). You (as a novice) can pretty much just startup a Mac and start working. Linux will be more of a learning curve and will come with more frustration.

Both will be more responsive (even on older equipment), at least in my experience, than Vista on newer/newest equipment.

I have been using OS X since 10.0 and running Linux since RH 6.x. I currently run OS X and Ubuntu and love them both for different reasons.