Not a hobbyist at all, Evo. Something that just works sounds good to me! Saab Dastard's link seems to indicate there is no problem with cross-platform networking as a basic principle, so Mrs B can stick with the Windows computer.
But what about my MS Office files? It appears AppleWorks is the default word processing software on new Macs. Are MS Office files fully compatible with the basic software or will I have to buy Word for Mac?
Lastly, I was just looking at the G5 iMac on the apple website. They don't show a case; is everything really contained in that one piece?